Displaying publications 1 - 20 of 92 in total

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  1. Fulltext Survivin expression correlates with unfavourable prognoses in invasive ductal carcinoma of the breast
    Al-Joudi FS, Iskandar ZA, Imran AK
    Med J Malaysia, 2007 Mar;62(1):6-8.
    PMID: 17682561 MyJurnal
    Survivin is a 16.5-kDa intracellular protein also known as AP14 or BIRC5. It inhibits apoptosis and regulates cell division and belongs to the inhibitors of apoptosis (IAP) gene family. In the majority of neoplasms investigated for survivin expression, high levels of the IAP proteins were predictive of tumour progression, either in terms of disease-free survival or overall survival, thus providing significant prognostic information. Hence, the prognostic value of survivin expression in tumour masses of invasive ductal carcinoma has been investigated. It was found that negative and low expression of survivin correlated significantly with favourable outcomes. Conversely, high expression correlated with unfavourable outcomes. The five-year survival rate was higher among the cases with low and negative survivin expression, compared to those with higher survivin expression. However, this correlation was found to be insignificant statistically. Furthermore, a statistical model has been devised to explain the combined effects of survivin expression and its sub-cellular localisation, p-53 expression and lymph nodal involvement, on the outcomes of these patients.
    Matched MeSH terms: Microtubule-Associated Proteins/antagonists & inhibitors; Neoplasm Proteins/antagonists & inhibitors
  2. Tocotrienol-treated MCF-7 human breast cancer cells show down-regulation of API5 and up-regulation of MIG6 genes
    Ramdas P, Rajihuzzaman M, Veerasenan SD, Selvaduray KR, Nesaretnam K, Radhakrishnan AK
    Cancer Genomics Proteomics, 2011 Jan-Feb;8(1):19-31.
    PMID: 21289334
    Tocotrienols belong to the vitamin E family and have multiple anticancer effects, such as antiproliferative, antioxidant, pro-apoptosis and antimetastatic. This study aimed to identify the genes that are regulated in human breast cancer cells following exposure to various isomers of vitamin E as these may be potential targets for the treatment of breast cancer.
    Matched MeSH terms: Nuclear Proteins/antagonists & inhibitors; Apoptosis Regulatory Proteins/antagonists & inhibitors
  3. In vitro anticancer properties and biological evaluation of novel natural alkaloid jerantinine B
    Qazzaz ME, Raja VJ, Lim KH, Kam TS, Lee JB, Gershkovich P, et al.
    Cancer Lett, 2016 Jan 28;370(2):185-97.
    PMID: 26515390 DOI: 10.1016/j.canlet.2015.10.013
    Natural products play a pivotal role in medicine especially in the cancer arena. Many drugs that are currently used in cancer chemotherapy originated from or were inspired by nature. Jerantinine B (JB) is one of seven novel Aspidosperma indole alkaloids isolated from the leaf extract of Tabernaemontana corymbosa. Preliminary antiproliferative assays revealed that JB and JB acetate significantly inhibited growth and colony formation, accompanied by time- and dose-dependent apoptosis induction in human cancer cell lines. JB significantly arrested cells at the G2/M cell cycle phase, potently inhibiting tubulin polymerisation. Polo-like kinase 1 (PLK1; an early trigger for the G2/M transition) was also dose-dependently inhibited by JB (IC50 1.5 µM). Furthermore, JB provoked significant increases in reactive oxygen species (ROS). Annexin V+ cell populations, dose-dependent accumulation of cleaved-PARP and caspase 3/7 activation, and reduced Bcl-2 and Mcl-1 expression confirm apoptosis induction. Preclinical in silico biopharmaceutical assessment of JB calculated rapid absorption and bioavailability >70%. Doses of 8-16 mg/kg JB were predicted to maintain unbound plasma concentrations >GI50 values in mice during efficacy studies. These findings advocate continued development of JB as a potential chemotherapeutic agent.
    Matched MeSH terms: Proto-Oncogene Proteins/antagonists & inhibitors; Cell Cycle Proteins/antagonists & inhibitors
  4. Fulltext Doxycycline Interferes with Zika Virus Serine Protease and Inhibits Virus Replication in Human Skin Fibroblasts
    Chong Teoh T, J Al-Harbi S, Abdulrahman AY, Rothan HA
    Molecules, 2021 Jul 16;26(14).
    PMID: 34299596 DOI: 10.3390/molecules26144321
    Zika virus (ZIKV) represents a re-emerging threat to global health due to its association with congenital birth defects. ZIKV NS2B-NS3 protease is crucial for virus replication by cleaving viral polyprotein at various junctions to release viral proteins and cause cytotoxic effects in ZIKV-infected cells. This study characterized the inhibitory effects of doxycycline against ZIKV NS2B-NS3 protease and viral replication in human skin cells. The in silico data showed that doxycycline binds to the active site of ZIKV protease at a low docking energy (-7.8 Kcal/mol) via four hydrogen bonds with the protease residues TYR1130, SER1135, GLY1151, and ASP83. Doxycycline efficiently inhibited viral NS2B-NS3 protease at average human temperature (37 °C) and human temperature with a high fever during virus infection (40 °C). Interestingly, doxycycline showed a higher inhibitory effect at 40 °C (IC50 = 5.3 µM) compared to 37 °C (9.9 µM). The virus replication was considerably reduced by increasing the concentration of doxycycline. An approximately 50% reduction in virus replication was observed at 20 µM of doxycycline. Treatment with 20 µM of doxycycline reduced the cytopathic effects (CPE), and the 40 µM of doxycycline almost eliminated the CPE of human skin cells. This study showed that doxycycline binds to the ZIKV protease and inhibits its catalytic activity at a low micro-molecular concentration range. Treatment of human skin fibroblast with doxycycline eliminated ZIKV infection and protected the cells against the cytopathic effects of the infection.
    Matched MeSH terms: Viral Proteins/antagonists & inhibitors*; Viral Nonstructural Proteins/antagonists & inhibitors*
  5. Disruption of repressive p130-DREAM complexes by human papillomavirus 16 E6/E7 oncoproteins is required for cell-cycle progression in cervical cancer cells
    Nor Rashid N, Yusof R, Watson RJ
    J Gen Virol, 2011 Nov;92(Pt 11):2620-2627.
    PMID: 21813705 DOI: 10.1099/vir.0.035352-0
    Human papillomaviruses (HPVs) with tropism for mucosal epithelia are the major aetiological factors in cervical cancer. Most cancers are associated with so-called high-risk HPV types, in particular HPV16, and constitutive expression of the HPV16 E6 and E7 oncoproteins is critical for malignant transformation in infected keratinocytes. E6 and E7 bind to and inactivate the cellular tumour suppressors p53 and Rb, respectively, thus delaying differentiation and inducing proliferation in suprabasal keratinocytes to enable HPV replication. One member of the Rb family, p130, appears to be a particularly important target for E7 in promoting S-phase entry. Recent evidence indicates that p130 regulates cell-cycle progression as part of a large protein complex termed DREAM. The composition of DREAM is cell cycle-regulated, associating with E2F4 and p130 in G0/G1 and with the B-myb transcription factor in S/G2. In this study, we addressed whether p130-DREAM is disrupted in HPV16-transformed cervical cancer cells and whether this is a critical function for E6/E7. We found that p130-DREAM was greatly diminished in HPV16-transformed cervical carcinoma cells (CaSki and SiHa) compared with control cell lines; however, when E6/E7 expression was targeted by specific small hairpin RNAs, p130-DREAM was reformed and the cell cycle was arrested. We further demonstrated that the profound G1 arrest in E7-depleted CaSki cells was dependent on p130-DREAM reformation by also targeting the expression of the DREAM component Lin-54 and p130. The results show that continued HPV16 E6/E7 expression is necessary in cervical cancer cells to prevent cell-cycle arrest by a repressive p130-DREAM complex.
    Matched MeSH terms: Repressor Proteins/antagonists & inhibitors; Kv Channel-Interacting Proteins/antagonists & inhibitors
  6. Fulltext Potential inhibitors for isocitrate lyase of Mycobacterium tuberculosis and non-M. tuberculosis: a summary
    Lee YV, Wahab HA, Choong YS
    Biomed Res Int, 2015;2015:895453.
    PMID: 25649791 DOI: 10.1155/2015/895453
    Isocitrate lyase (ICL) is the first enzyme involved in glyoxylate cycle. Many plants and microorganisms are relying on glyoxylate cycle enzymes to survive upon downregulation of tricarboxylic acid cycle (TCA cycle), especially Mycobacterium tuberculosis (MTB). In fact, ICL is a potential drug target for MTB in dormancy. With the urge for new antitubercular drug to overcome tuberculosis treat such as multidrug resistant strain and HIV-coinfection, the pace of drug discovery has to be increased. There are many approaches to discovering potential inhibitor for MTB ICL and we hereby review the updated list of them. The potential inhibitors can be either a natural compound or synthetic compound. Moreover, these compounds are not necessary to be discovered only from MTB ICL, as it can also be discovered by a non-MTB ICL. Our review is categorized into four sections, namely, (a) MTB ICL with natural compounds; (b) MTB ICL with synthetic compounds; (c) non-MTB ICL with natural compounds; and (d) non-MTB ICL with synthetic compounds. Each of the approaches is capable of overcoming different challenges of inhibitor discovery. We hope that this paper will benefit the discovery of better inhibitor for ICL.
    Matched MeSH terms: Bacterial Proteins/antagonists & inhibitors*
  7. Fulltext Inhibitors of the glyoxylate cycle enzyme ICL1 in Candida albicans for potential use as antifungal agents
    Cheah HL, Lim V, Sandai D
    PLoS One, 2014;9(4):e95951.
    PMID: 24781056 DOI: 10.1371/journal.pone.0095951
    Candida albicans is an opportunistic pathogen that causes candidiasis in humans. In recent years, metabolic pathways in C. albicans have been explored as potential antifungal targets to treat candidiasis. The glyoxylate cycle, which enables C. albicans to survive in nutrient-limited host niches and its. Key enzymes (e.g., isocitrate lyase (ICL1), are particularly attractive antifungal targets for C. albicans. In this study, we used a new screening approach that better reflects the physiological environment that C. albicans cells experience during infection to identify potential inhibitors of ICL. Three compounds (caffeic acid (CAFF), rosmarinic acid (ROS), and apigenin (API)) were found to have antifungal activity against C. albicans when tested under glucose-depleted conditions. We further confirmed the inhibitory potential of these compounds against ICL using the ICL enzyme assay. Lastly, we assessed the bioavailability and toxicity of these compounds using Lipinski's rule-of-five and ADMET analysis.
    Matched MeSH terms: Fungal Proteins/antagonists & inhibitors*
  8. Fulltext Preventive inositol hexaphosphate extracted from rice bran inhibits colorectal cancer through involvement of Wnt/β-catenin and COX-2 pathways
    Shafie NH, Mohd Esa N, Ithnin H, Md Akim A, Saad N, Pandurangan AK
    Biomed Res Int, 2013;2013:681027.
    PMID: 24260743 DOI: 10.1155/2013/681027
    Nutritional or dietary factors have drawn attention due to their potential as an effective chemopreventive agent, which is considered a more rational strategy in cancer treatment. This study was designed to evaluate the effect of IP₆ extracted from rice bran on azoxymethane- (AOM-) induced colorectal cancer (CRC) in rats. Initially, male Sprague Dawley rats were divided into 5 groups, with 6 rats in each group. The rats received two intraperitoneal (i.p.) injections of AOM in saline (15 mg/kg body weight) over a 2-week period to induce CRC. IP₆ was given in three concentrations, 0.2% (w/v), 0.5% (w/v), and 1.0% (w/v), via drinking water for 16 weeks. The deregulation of the Wnt/β-catenin signaling pathway and the expression of cyclooxygenase (COX)-2 have been implicated in colorectal tumorigenesis. β-Catenin and COX-2 expressions were analysed using the quantitative RT-PCR and Western blotting. Herein, we reported that the administration of IP₆ markedly suppressed the incidence of tumors when compared to the control. Interestingly, the administration of IP₆ had also markedly decreased β-catenin and COX-2 in colon tumors. Thus, the downregulation of β-catenin and COX-2 could play a role in inhibiting the CRC development induced by IP₆ and thereby act as a potent anticancer agent.
    Matched MeSH terms: Neoplasm Proteins/antagonists & inhibitors*
  9. Inhibitory effect of doxycycline against dengue virus replication in vitro
    Rothan HA, Mohamed Z, Paydar M, Rahman NA, Yusof R
    Arch Virol, 2014 Apr;159(4):711-8.
    PMID: 24142271 DOI: 10.1007/s00705-013-1880-7
    Doxycycline is an antibiotic derived from tetracycline that possesses antimicrobial and anti-inflammatory activities. Antiviral activity of doxycycline against dengue virus has been reported previously; however, its anti-dengue properties need further investigation. This study was conducted to determine the potential activity of doxycycline against dengue virus replication in vitro. Doxycycline inhibited the dengue virus serine protease (DENV2 NS2B-NS3pro) with an IC50 value of 52.3 ± 6.2 μM at 37 °C (normal human temperature) and 26.7 ± 5.3 μM at 40 °C (high fever temperature). The antiviral activity of doxycycline was first tested at different concentrations against DENV2 using a plaque-formation assay. The virus titter decreased significantly after applying doxycycline at levels lower than its 50 % cytotoxic concentration (CC50, 100 μM), showing concentration-dependent inhibition with a 50 % effective concentration (EC50) of approximately 50 μM. Doxycycline significantly inhibited viral entry and post-infection replication of the four dengue serotypes, with serotype-specific inhibition (high activity against DENV2 and DENV4 compared to DENV1 and DENV3). Collectively, these findings underline the need for further experimental and clinical studies on doxycycline, utilizing its anti-dengue and anti-inflammatory activities to attenuate the clinical symptoms of dengue virus infection.
    Matched MeSH terms: Viral Nonstructural Proteins/antagonists & inhibitors
  10. Fulltext Effects of Andrographis paniculata and Orthosiphon stamineus extracts on the glucuronidation of 4-methylumbelliferone in human UGT isoforms
    Ismail S, Hanapi NA, Ab Halim MR, Uchaipichat V, Mackenzie PI
    Molecules, 2010 May 14;15(5):3578-92.
    PMID: 20657500 DOI: 10.3390/molecules15053578
    The effects of Andrographis paniculata and Orthosiphon stamineus extracts on the in vitro glucuronidation of 4-methylumbelliferone (4MU) by recombinant human UGTs, UGT1A1, UGT1A3, UGT1A6, UGT1A7, UGT1A8, UGT1A10, UGT2B7 and UGT2B15 were determined. The potential inhibitory effects of both of the extracts on the activity of each of the UGT isoforms were investigated using 4MU as the substrate. Incubations contained UDP-glucuronic acid (UDPGA) as the cofactor, MgCl(2), cell lysate of respective isoform, and 4MU at the approximate apparent K(m) or S(50) value of each isoform. Final concentrations of Andrographis paniculata and Orthosiphon stamineus extracts used were 0.025, 0.25, 2.5, 25 and 50 microg/mL and 0.01, 0.10, 1.0, 10 and 50 microg/mL respectively. Both extracts variably inhibited the activity of most of the isoforms in a concentration dependent manner. Andrographis paniculata extract was the better inhibitor of all the isoforms studied (IC(50) 1.70 microg/mL for UGT1A3, 2.57 microg/mL for UGT1A8, 2.82 microg/mL for UGT2B7, 5.00 micorg/mL for UGT1A1, 5.66 microg/mL for UGT1A6, 9.88 microg/mL for UGT1A7 and 15.66 microg/mL for UGT1A10). Both extracts showed less than 70% inhibition of UGT2B15, so the IC(50) values were >50 microg/mL. The inhibition of human UGTs by Andrographis paniculata and Orthosiphon stamineus extracts in vitro suggests a potential for drug-herbal extract interactions in the therapeutic setting.
    Matched MeSH terms: Monosaccharide Transport Proteins/antagonists & inhibitors*
  11. Development of an inhibitive enzyme assay for copper
    Shukor MY, Bakar NA, Othman AR, Yunus I, Shamaan NA, Syed MA
    J Environ Biol, 2009 Jan;30(1):39-44.
    PMID: 20112861
    In this work the development of an inhibitive assay for copper using the molybdenum-reducing enzyme assay is presented. The enzyme is assayed using 12-molybdophosphoric acid at pH 5.0 as an electron acceptor substrate and NADH as the electron donor substrate. The enzyme converts the yellowish solution into a deep blue solution. The assay is based on the ability of copper to inhibit the molybdenum-reducing enzyme from the molybdate-reducing Serratia sp. Strain DRY5. Other heavy metals tested did not inhibit the enzyme at 10 mg l(-1). The best model with high regression coefficient to measure copper inhibition is one-phase binding. The calculated IC50 (concentration causing 50% inhibition) is 0.099 mg l(-1) and the regression coefficient is 0.98. The comparative LC50, EC50 and IC50 data for copper in different toxicity tests show that the IC50 value for copper in this study is lower than those for immobilized urease, bromelain, Rainbow trout, R. meliloti, Baker's Yeast dehydrogenase activity Spirillum volutans, P. fluorescens, Aeromonas hydrophilia and synthetic activated sludge assays. However the IC50 value is higher than those for Ulva pertusa and papain assays, but within the reported range for Daphnia magna and Microtox assays.
    Matched MeSH terms: Bacterial Proteins/antagonists & inhibitors
  12. Pharmacological modulation of oncogenic Ras by natural products and their derivatives: Renewed hope in the discovery of novel anti-Ras drugs
    Quah SY, Tan MS, Teh YH, Stanslas J
    Pharmacol Ther, 2016 06;162:35-57.
    PMID: 27016467 DOI: 10.1016/j.pharmthera.2016.03.010
    Oncogenic rat sarcoma (Ras) is linked to the most fatal cancers such as those of the pancreas, colon, and lung. Decades of research to discover an efficacious drug that can block oncogenic Ras signaling have yielded disappointing results; thus, Ras was considered "undruggable" until recently. Inhibitors that directly target Ras by binding to previously undiscovered pockets have been recently identified. Some of these molecules are either isolated from natural products or derived from natural compounds. In this review, we described the potential of these compounds and other inhibitors of Ras signaling in drugging Ras. We highlighted the modes of action of these compounds in suppressing signaling pathways activated by oncogenic Ras, such as mitogen-activated protein kinase (MAPK) signaling and the phosphoinositide-3-kinase (PI3K) pathways. The anti-Ras strategy of these compounds can be categorized into four main types: inhibition of Ras-effector interaction, interference of Ras membrane association, prevention of Ras-guanosine triphosphate (GTP) formation, and downregulation of Ras proteins. Another promising strategy that must be validated experimentally is enhancement of the intrinsic Ras-guanosine triphosphatase (GTPase) activity by small chemical entities. Among the inhibitors of Ras signaling that were reported thus far, salirasib and TLN-4601 have been tested for their clinical efficacy. Although both compounds passed phase I trials, they failed in their respective phase II trials. Therefore, new compounds of natural origin with relevant clinical activity against Ras-driven malignancies are urgently needed. Apart from salirasib and TLN-4601, some other compounds with a proven inhibitory effect on Ras signaling include derivatives of salirasib, sulindac, polyamine, andrographolide, lipstatin, levoglucosenone, rasfonin, and quercetin.
    Matched MeSH terms: ras Proteins/antagonists & inhibitors*
  13. Inhibition and Substrate Specificity Properties of FKBP22 from a Psychrotrophic Bacterium, Shewanella sp. SIB1
    Budiman C, Lindang HU, Cheong BE, Rodrigues KF
    Protein J, 2018 06;37(3):270-279.
    PMID: 29761378 DOI: 10.1007/s10930-018-9772-z
    SIB1 FKBP22 is a peptidyl prolyl cis-trans isomerase (PPIase) member from a psychrotrophic bacterium, Shewanella sp. SIB1, consisting of N- and C-domains responsible for dimerization and catalytic PPIase activity, respectively. This protein was assumed to be involved in cold adaptation of SIB1 cells through its dual activity of PPIase activity and chaperone like-function. Nevertheless, the catalytic inhibition by FK506 and its substrate specificity remain unknown. Besides, ability of SIB1 FKBP22 to inhibit phosphatase activity of calcinuerin is also interesting to be studied since it may reflect wider cellular functions of SIB1 FKBP22. In this study, we found that wild type (WT) SIB1 FKBP22 bound to FK506 with IC50 of 77.55 nM. This value is comparable to that of monomeric mutants (NNC-FKBP22, C-domain+ and V37R/L41R mutants), yet significantly higher than that of active site mutant (R142A). In addition, WT SIB1 FKBP22 and monomeric variants were found to prefer hydrophobic residues preceding proline. Meanwhile, R142A mutant has wider preferences on bulkier hydrophobic residues due to increasing hydrophobicity and binding pocket space. Surprisingly, in the absence of FK506, SIB1 FKBP22 and its variants inhibited, with the exception of N-domain, calcineurin phosphatase activity, albeit low. The inhibition of SIB1 FKBP22 by FK506 is dramatically increased in the presence of FK506. Altogether, we proposed that local structure at substrate binding pocket of C-domain plays crucial role for the binding of FK506 and peptide substrate preferences. In addition, C-domain is essential for inhibition, while dimerization state is important for optimum inhibition through efficient binding to calcineurin.
    Matched MeSH terms: Bacterial Proteins/antagonists & inhibitors*
  14. Fulltext Carvacrol derivatives as mushroom tyrosinase inhibitors; synthesis, kinetics mechanism and molecular docking studies
    Ashraf Z, Rafiq M, Nadeem H, Hassan M, Afzal S, Waseem M, et al.
    PLoS One, 2017;12(5):e0178069.
    PMID: 28542395 DOI: 10.1371/journal.pone.0178069
    The present work describesthe development of highly potent mushroom tyrosinase inhibitor better than the standard kojic acid. Carvacrol derivatives 4a-f and 6a-d having substituted benzoic acid and cinnamic acidresidues were synthesized with the aim to possess potent tyrosinase inhibitory activity.The structures of the synthesized compounds were ascertained by their spectroscopic data (FTIR, 1HNMR, 13CNMR and Mass Spectroscopy).Mushroom tyrosinase inhibitory activity of synthesized compounds was determined and it was found that one of the derivative 6c possess higher activity (IC50 0.0167μM) than standard kojic acid (IC50 16.69μM). The derivatives 4c and 6b also showed good tyrosinase inhibitory activity with (IC50 16.69μM) and (IC50 16.69μM) respectively.Lineweaver-Burk and Dixon plots were used for the determination of kinetic mechanism of the compounds 4c and 6b and 6c. The kinetic analysis revealed that compounds 4c and 6b showed mixed-type inhibition while 6c is a non-competitive inhibitor having Ki values19 μM, 10 μM, and 0.05 μMrespectively. The enzyme inhibitory kinetics further showed thatcompounds 6b and 6c formed irreversible enzyme inhibitor complex while 4c bind reversibly with mushroom tyrosinase.The docking studies showed that compound 6c have maximum binding affinity against mushroom tyrosinase (PDBID: 2Y9X) with binding energy value (-7.90 kcal/mol) as compared to others.The 2-hydroxy group in compound 6c interacts with amino acid HIS85 which is present in active binding site. The wet lab results are in good agreement with the dry lab findings.Based upon our investigation we may propose that the compound 6c is promising candidate for the development of safe cosmetic agent.
    Matched MeSH terms: Fungal Proteins/antagonists & inhibitors*
  15. Expression and characterization of functional domains of FK506-binding protein 35 from Plasmodium knowlesi
    Goh CKW, Silvester J, Wan Mahadi WNS, Chin LP, Ying LT, Leow TC, et al.
    Protein Eng. Des. Sel., 2018 12 01;31(12):489-498.
    PMID: 31120120 DOI: 10.1093/protein/gzz008
    The FK506-binding protein of Plasmodium knowlesi (Pk-FKBP35) is considerably a viable antimalarial drug target, which belongs to the peptidyl-prolyl cis-trans isomerase (PPIase) protein family member. Structurally, this protein consists of an N-terminal FK506-binding domain (FKBD) and a C-terminal tetratricopeptide repeat domain (TPRD). This study aims to decipher functional properties of these domains as a platform for development of novel antimalarial drugs. Accordingly, full-length Pk-FKBP35 as well as its isolated domains, Pk-FKBD and Pk-TPRD were overexpressed, purified, and characterized. The results showed that catalytic PPIase activity was confined to the full-length Pk-FKBP35 and Pk-FKBD, suggesting that the catalytic activity is structurally regulated by the FKBD. Meanwhile, oligomerization analysis revealed that Pk-TPRD is essential for dimerization. Asp55, Arg60, Trp77 and Phe117 in the Pk-FKBD were considerably important for catalysis as underlined by significant reduction of PPIase activity upon mutations at these residues. Further, inhibition activity of Pk-FKBP35 towards calcineurin phosphatase activity revealed that the presence of FKBD is essential for the inhibitory property, while TPRD may be important for efficient binding to calcineurin. We then discussed possible roles of FKBP35 in Plasmodium cells and proposed mechanisms by which the immunosuppressive drug, FK506, interacts with the protein.
    Matched MeSH terms: Tacrolimus Binding Proteins/antagonists & inhibitors
  16. Fulltext Neuraminidase Inhibitor of Garcinia atroviridis L. Fruits and Leaves Using Partial Purification and Molecular Characterization
    Muchtaridi M, Nuwarda RF, Ikram EHK, Abdul Rahim AS, Gazzali AM, Wahab HA
    Molecules, 2022 Jan 30;27(3).
    PMID: 35164214 DOI: 10.3390/molecules27030949
    Neuraminidase (NA) is an enzyme that prevents virions from aggregating within the host cell and promotes cell-to-cell spread by cleaving glycosidic linkages to sialic acid. The best-known neuraminidase is the viral neuraminidase, which present in the influenza virus. Thus, the development of anti-influenza drugs that inhibit NA has emerged as an important and intriguing approach in the treatment of influenza. Garcinia atroviridis L. (GA) dried fruits (GAF) are used commercially as seasoning and in beverages. The main objective of this study was to identify a new potential neuraminidase inhibitor from GA. A bioassay-guided fractionation method was applied to obtain the bioactive compounds leading to the identification of garcinia acid and naringenin. In an enzyme inhibition study, garcinia acid demonstrated the highest activity when compared to naringenin. Garcinia acid had the highest activity, with an IC50 of 17.34-17.53 µg/mL or 91.22-92.21 µM against Clostridium perfringens-NA, and 56.71-57.85 µg/mL or 298.32-304.31 µM against H1N1-NA. Based on molecular docking results, garcinia acid interacted with the triad arginine residues (Arg118, Arg292, and Arg371) of the viral neuraminidase, implying that this compound has the potential to act as a NA enzyme inhibitor.
    Matched MeSH terms: Viral Proteins/antagonists & inhibitors
  17. Inhibition and kinetic studies of cellulose- and hemicellulose-degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds
    Surendran A, Siddiqui Y, Ali NS, Manickam S
    J Appl Microbiol, 2018 Jun;124(6):1544-1555.
    PMID: 29405525 DOI: 10.1111/jam.13717
    AIM: Ganoderma sp, the causal pathogen of the basal stem rot (BSR) disease of oil palm, secretes extracellular hydrolytic enzymes. These play an important role in the pathogenesis of BSR by nourishing the pathogen through the digestion of cellulose and hemicellulose of the host tissue. Active suppression of hydrolytic enzymes secreted by Ganoderma boninense by various naturally occurring phenolic compounds and estimation of their efficacy on pathogen suppression is focused in this study.

    METHODS AND RESULTS: Ten naturally occurring phenolic compounds were assessed for their inhibitory effect on the hydrolytic enzymes of G. boninense. The enzyme kinetics (Vmax and Km ) and the stability of the hydrolytic enzymes were also characterized. The selected compounds had shown inhibitory effect at various concentrations. Two types of inhibitions namely uncompetitive and noncompetitive were observed in the presence of phenolic compounds. Among all the phenolic compounds tested, benzoic acid was the most effective compound suppressive to the growth and production of hydrolytic enzymes secreted by G. boninense. The phenolic compounds as inhibitory agents can be a better replacement for the metal ions which are known as conventional inhibitors till date. The three hydrolytic enzymes were stable in a wide range of pH and temperature.

    CONCLUSION: These findings highlight the efficacy of the applications of phenolic compounds to control Ganoderma.

    SIGNIFICANCE AND IMPACT OF THE STUDY: The study has proved a replacement for chemical controls of G. boninense with naturally occurring phenolic compounds.

    Matched MeSH terms: Fungal Proteins/antagonists & inhibitors
  18. Fulltext The nucleoprotein of influenza A virus induces p53 signaling and apoptosis via attenuation of host ubiquitin ligase RNF43
    Nailwal H, Sharma S, Mayank AK, Lal SK
    Cell Death Dis, 2015 May 21;6:e1768.
    PMID: 25996295 DOI: 10.1038/cddis.2015.131
    The interplay between influenza virus and host factors to support the viral life cycle is well documented. Influenza A virus (IAV) proteins interact with an array of cellular proteins and hijack host pathways which are at the helm of cellular responses to facilitate virus invasion. The multifaceted nature of the ubiquitination pathway for protein regulation makes it a vulnerable target of many viruses including IAV. To this end we conducted a yeast two-hybrid screen to search for cellular ubiquitin ligases important for influenza virus replication. We identified host protein, RING finger protein 43 (RNF43), a RING-type E3 ubiquitin ligase, as a novel interactor of nucleoprotein (NP) of IAV and an essential partner to induce NP-driven p53-mediated apoptosis in IAV-infected cells. In this study, we demonstrate that IAV leads to attenuation of RNF43 transcripts and hence its respective protein levels in the cellular milieu whereas in RNF43 depleted cells, viral replication was escalated several folds. Moreover, RNF43 polyubiquitinates p53 which further leads to its destabilization resulting in a decrease in induction of the p53 apoptotic pathway, a hitherto unknown process targeted by NP for p53 stabilization and accumulation. Collectively, these results conclude that NP targets RNF43 to modulate p53 ubiquitination levels and hence causes p53 stabilization which is conducive to an enhanced apoptosis level in the host cells. In conclusion, our study unravels a novel strategy adopted by IAV for utilizing the much conserved ubiquitin proteasomal pathway.
    Matched MeSH terms: DNA-Binding Proteins/antagonists & inhibitors; Oncogene Proteins/antagonists & inhibitors
  19. Fulltext WDR5, ASH2L, and RBBP5 control the efficiency of FOS transcript processing
    Teoh PL, Sharrocks AD
    Cell Mol Biol Lett, 2014 Jun;19(2):215-32.
    PMID: 24715476 DOI: 10.2478/s11658-014-0190-8
    H3K4 trimethylation is strongly associated with active transcription. The deposition of this mark is catalyzed by SET-domain methyltransferases, which consist of a subcomplex containing WDR5, ASH2L, and RBBP5 (the WAR subcomplex); a catalytic SET-domain protein; and additional complexspecific subunits. The ERK MAPK pathway also plays an important role in gene regulation via phosphorylation of transcription factors, co-regulators, or histone modifier complexes. However, the potential interactions between these two pathways remain largely unexplored. We investigated their potential interplay in terms of the regulation of the immediate early gene (IEG) regulatory network. We found that depletion of components of the WAR subcomplex led to increased levels of unspliced transcripts of IEGs that did not necessarily reflect changes in their mature transcripts. This occurs in a manner independent from changes in the H3K4me3 levels at the promoter region. We focused on FOS and found that the depletion of WAR subcomplex components affected the efficiency of FOS transcript processing. Our findings show a new aspect of WAR subcomplex function in coordinating active transcription with efficient pre-mRNA processing.
    Matched MeSH terms: DNA-Binding Proteins/antagonists & inhibitors; Nuclear Proteins/antagonists & inhibitors
  20. Fulltext Identification of Peptide Inhibitors of Enveloped Viruses Using Support Vector Machine
    Xu Y, Yu S, Zou JW, Hu G, Rahman NA, Othman RB, et al.
    PLoS One, 2015;10(11):e0144171.
    PMID: 26636321 DOI: 10.1371/journal.pone.0144171
    The peptides derived from envelope proteins have been shown to inhibit the protein-protein interactions in the virus membrane fusion process and thus have a great potential to be developed into effective antiviral therapies. There are three types of envelope proteins each exhibiting distinct structure folds. Although the exact fusion mechanism remains elusive, it was suggested that the three classes of viral fusion proteins share a similar mechanism of membrane fusion. The common mechanism of action makes it possible to correlate the properties of self-derived peptide inhibitors with their activities. Here we developed a support vector machine model using sequence-based statistical scores of self-derived peptide inhibitors as input features to correlate with their activities. The model displayed 92% prediction accuracy with the Matthew's correlation coefficient of 0.84, obviously superior to those using physicochemical properties and amino acid decomposition as input. The predictive support vector machine model for self- derived peptides of envelope proteins would be useful in development of antiviral peptide inhibitors targeting the virus fusion process.
    Matched MeSH terms: Viral Envelope Proteins/antagonists & inhibitors*
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