Displaying publications 1 - 20 of 126 in total

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  1. Frimayanti N, Zain SM, Lee VS, Wahab HA, Yusof R, Abd Rahman N
    In Silico Biol. (Gedrukt), 2011;11(1-2):29-37.
    PMID: 22475750 DOI: 10.3233/ISB-2012-0442
    Publication year=2011-2012
    Matched MeSH terms: Serine Endopeptidases/drug effects*
  2. Azmi NH, Ismail M, Ismail N, Imam MU, Alitheen NB, Abdullah MA
    PMID: 26858770 DOI: 10.1155/2015/153684
    The pathogenesis of Alzheimer's disease involves complex etiological factors, of which the deposition of beta-amyloid (Aβ) protein and oxidative stress have been strongly implicated. We explored the effects of H2O2, which is a precursor for highly reactive hydroxyl radicals, on neurotoxicity and genes related to AD on neuronal cells. Candidate bioactive compounds responsible for the effects were quantified using HPLC-DAD. Additionally, the effects of germinated brown rice (GBR) on the morphology of Aβ(1-42) were assessed by Transmission Electron Microscopy and its regulatory effects on gene expressions were explored. The results showed that GBR extract had several phenolic compounds and γ-oryzanol and altered the structure of Aβ(1-42) suggesting an antiamyloidogenic effect. GBR was also able to attenuate the oxidative effects of H2O2 as implied by reduced LDH release and intracellular ROS generation. Furthermore, gene expression analyses showed that the neuroprotective effects of GBR were partly mediated through transcriptional regulation of multiple genes including Presenilins, APP, BACE1, BACE2, ADAM10, Neprilysin, and LRP1. Our findings showed that GBR exhibited neuroprotective properties via transcriptional regulation of APP metabolism with potential impact on Aβ aggregation. These findings can have important implications for the management of neurodegenerative diseases like AD and are worth exploring further.
    Matched MeSH terms: Aspartic Acid Endopeptidases
  3. Roslan, J., Mustapa Kamal, S.M., Md. Yunos, K.F., Abdullah, N.
    MyJurnal
    Fish protein hydrolysate was recovered from tilapia by-product (TB) through enzymatic hydrolysis using alcalase enzyme. Hydrolysis reaction of TB was monitored according to the degree of hydrolysis (DH) by employing O-phtaldialdehyde (OPA) method. Optimization process for obtaining high yield of TB protein hydrolysate was performed using response surface methodology (RSM) by optimizing a combination of four independent variables namely, pH (6.5-8.5), temperature (55-70oC), substrate concentration (10-17.5% w/v), and enzyme concentration (1.5-3.5% w/w) with (DH) as a response. The optimum enzymatic hydrolysis conditions were obtained at pH 7.5, temperature of 60oC, substrate concentration of 15% (w/v) and 2.5% (w/w) of enzyme concentration and yielded about 20.20% of DH after hydrolyzing for 120 min. RSM generated model predicted that 20.42% of DH could be achieved at these conditions and this model was valid based on the DH value obtained from the experimental study (20.31%) which was quite similar with the predicted value. High yield of DH obtained from the optimization process could produce fish protein hydrolysate with good nutritional and functional properties.
    Matched MeSH terms: Endopeptidases
  4. Chan LC, Mat Yassim AS, Ahmad Fuaad AAH, Leow TC, Sabri S, Radin Yahaya RS, et al.
    Sci Rep, 2023 Nov 17;13(1):20178.
    PMID: 37978223 DOI: 10.1038/s41598-023-47511-z
    COVID-19 results from SARS-CoV-2, which mutates frequently, challenging current treatments. Therefore, it is critical to develop new therapeutic drugs against this disease. This study explores the interaction between SARS-CoV-2 3CLpro and RetroMAD1, a well-characterized coronavirus protein and potential drug target, using in-silico methods. The analysis through the HDOCK server showed stable complex formation with a binding energy of -12.3, the lowest among reference drugs. The RetroMAD1-3CLpro complex underwent a 100 ns molecular dynamics simulation (MDS) in an explicit solvation system, generating various trajectories, including RMSD, RMSF, hydrogen bonding, radius of gyration, and ligand binding energy. MDS results confirmed intact interactions within the RetroMAD1-3CLpro complex during simulations. In vitro experiments validated RetroMAD1's ability to inhibit 3CLpro enzyme activity and prevent SARS-CoV-2 infection in human bronchial cells. RetroMAD1 exhibited antiviral efficacy comparable to Remdesivir without cytotoxicity at effective concentrations. These results suggest RetroMAD1 as a potential drug candidate against SARS-CoV-2, warranting further in vivo and clinical studies to assess its efficiency.
    Matched MeSH terms: Cysteine Endopeptidases/metabolism
  5. Shafee N, AbuBakar S
    J Gen Virol, 2003 Aug;84(Pt 8):2191-2195.
    PMID: 12867651 DOI: 10.1099/vir.0.19022-0
    Apoptosis was detected in Vero cell cultures expressing transfected dengue virus type 2 (DENV-2) genes. Approximately 17.5 and 51.5 % of cells expressing NS3 serine protease and NS2B-NS3(185) serine protease precursor protein [NS2B-NS3(185)(pro)] genes, respectively, were apoptotic. The percentage of apoptotic cells was significantly higher in cell cultures expressing NS2B-NS3(185)(pro). NS2B-NS3(185)(pro) was detected as NS2B-NS3(185)(pro)-EGFP fusion protein in cytoplasmic vesicular structures in the apoptotic cells. Site-directed mutagenesis which replaced His(51) with Ala within the protease catalytic triad significantly reduced the ability of the expressed NS3 and NS2B-NS3(185)(pro) to induce apoptosis. Results from the present study showed that DENV-2-encoded NS3 serine protease induces apoptosis, which is enhanced in cells expressing its precursor, NS2B-NS3(185)(pro). These findings suggest the importance of NS2B as a cofactor to NS3 protease-induced apoptosis.
    Matched MeSH terms: Serine Endopeptidases
  6. Cheong HC, Lee CYQ, Cheok YY, Shankar EM, Sabet NS, Tan GMY, et al.
    Immunobiology, 2019 01;224(1):34-41.
    PMID: 30477893 DOI: 10.1016/j.imbio.2018.10.010
    BACKGROUND: Persistent inflammation caused by Chlamydia trachomatis in the female genital compartment represents one of the major causes of pelvic inflammatory disease (PID), ectopic pregnancy and infertility in females. Here, we examined the pro-inflammatory cytokine response following stimulation with three different types of C. trachomatis antigens, viz. chlamydial protease-like factor (CPAF), heat shock protein 60 (HSP60) and major outer membrane protein (MOMP).

    METHODS: A total of 19 patients with genital C. trachomatis infection and 10 age-matched healthy controls were recruited for the study. Peripheral blood mononuclear cells (PBMCs) isolated from genital C. trachomatis-infected females were cultured in the presence of CPAF, HSP60 and MOMP antigens, and cytokines were measured by ELISA assay.

    RESULTS: We reported that pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) were robustly secreted following antigenic exposure. Notably, CPAP and MOMP were more potent in triggering IL-1β, as compared to HSP60. Elevated levels of the proinflammatory cytokines were also noted in the samples infected with plasmid-bearing C. trachomatis as compared to those infected with plasmid-free strains.

    CONCLUSIONS: Our study highlights distinct ability of chlamydial antigens in triggering pro-inflammatory response in the host immune cells.

    Matched MeSH terms: Endopeptidases/metabolism*
  7. Mukhametov A, Newhouse EI, Aziz NA, Saito JA, Alam M
    J Mol Graph Model, 2014 Jul;52:103-13.
    PMID: 25023665 DOI: 10.1016/j.jmgm.2014.06.008
    The allosteric pocket of the Dengue virus (DENV2) NS2B/NS3 protease, which is proximal to its catalytic triad, represents a promising drug target (Othman et al., 2008). We have explored this binding site through large-scale virtual screening and molecular dynamics simulations followed by calculations of binding free energy. We propose two mechanisms for enzyme inhibition. A ligand may either destabilize electronic density or create steric effects relating to the catalytic triad residues NS3-HIS51, NS3-ASP75, and NS3-SER135. A ligand may also disrupt movement of the C-terminal of NS2B required for inter-conversion between the "open" and "closed" conformations. We found that chalcone and adenosine derivatives had the top potential for drug discovery hits, acting through both inhibitory mechanisms. Studying the molecular mechanisms of these compounds might be helpful in further investigations of the allosteric pocket and its potential for drug discovery.
    Matched MeSH terms: Serine Endopeptidases/metabolism*
  8. Mirza FJ, Zahid S, Amber S, Sumera, Jabeen H, Asim N, et al.
    Molecules, 2022 Oct 25;27(21).
    PMID: 36364071 DOI: 10.3390/molecules27217241
    Alzheimer's disease (AD) has been associated with the hallmark features of cholinergic dysfunction, amyloid beta (Aβ) aggregation and impaired synaptic transmission, which makes the associated proteins, such as β-site amyloid precursor protein cleaving enzyme 1 (BACE I), acetylcholine esterase (AChE) and synapsin I, II and III, major targets for therapeutic intervention. The present study investigated the therapeutic potential of three major phytochemicals of Rosmarinus officinalis, ursolic acid (UA), rosmarinic acid (RA) and carnosic acid (CA), based on their binding affinity with AD-associated proteins. Detailed docking studies were conducted using AutoDock vina followed by molecular dynamic (MD) simulations using Amber 20. The docking analysis of the selected molecules showed the binding energies of their interaction with the target proteins, while MD simulations comprising root mean square deviation (RMSD), root mean square fluctuation (RMSF) and molecular mechanics/generalized born surface area (MM/GBSA) binding free energy calculations were carried out to check the stability of bound complexes. The drug likeness and the pharmacokinetic properties of the selected molecules were also checked through the Lipinski filter and ADMETSAR analysis. All these bioactive compounds demonstrated strong binding affinity with AChE, BACE1 and synapsin I, II and III. The results showed UA and RA to be potential inhibitors of AChE and BACE1, exhibiting binding energies comparable to those of donepezil, used as a positive control. The drug likeness and pharmacokinetic properties of these compounds also demonstrated drug-like characteristics, indicating the need for further in vitro and in vivo investigations to ascertain their therapeutic potential for AD.
    Matched MeSH terms: Aspartic Acid Endopeptidases
  9. Alhabib KF, Al-Rasadi K, Almigbal TH, Batais MA, Al-Zakwani I, Al-Allaf FA, et al.
    PLoS One, 2021;16(6):e0251560.
    PMID: 34086694 DOI: 10.1371/journal.pone.0251560
    BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is a common autosomal dominant disorder that can result in premature atherosclerotic cardiovascular disease (ASCVD). Limited data are available worldwide about the prevalence and management of FH. Here, we aimed to estimate the prevalence and management of patients with FH in five Arabian Gulf countries (Saudi Arabia, Oman, United Arab Emirates, Kuwait, and Bahrain).

    METHODS: The multicentre, multinational Gulf FH registry included adults (≥18 years old) recruited from outpatient clinics in 14 tertiary-care centres across five Arabian Gulf countries over the last five years. The Gulf FH registry had four phases: 1- screening, 2- classification based on the Dutch Lipid Clinic Network, 3- genetic testing, and 4- follow-up.

    RESULTS: Among 34,366 screened patient records, 3713 patients had suspected FH (mean age: 49±15 years; 52% women) and 306 patients had definite or probable FH. Thus, the estimated FH prevalence was 0.9% (1:112). Treatments included high-intensity statin therapy (34%), ezetimibe (10%), and proprotein convertase subtilisin/kexin type 9 inhibitors (0.4%). Targets for low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol were achieved by 12% and 30%, respectively, of patients at high ASCVD risk, and by 3% and 6%, respectively, of patients at very high ASCVD risk (p <0.001; for both comparisons).

    CONCLUSIONS: This snap-shot study was the first to show the high estimated prevalence of FH in the Arabian Gulf region (about 3-fold the estimated prevalence worldwide), and is a "call-to-action" for further confirmation in future population studies. The small proportions of patients that achieved target LDL-C values implied that health care policies need to implement nation-wide screening, raise FH awareness, and improve management strategies for FH.

    Matched MeSH terms: Serine Endopeptidases/metabolism
  10. Amri Saroukolaei S, Pei Pei C, Shokri H, Asadi F
    J Mycol Med, 2012 Jun;22(2):149-59.
    PMID: 23518017 DOI: 10.1016/j.mycmed.2012.01.002
    To compare the specific intracellular proteinase A activity in clinical isolates of Candida species isolated from Iranian and Malaysian patients, the blood and kidneys of mice infected by Candida cells isolated from these human patients.
    Matched MeSH terms: Aspartic Acid Endopeptidases/isolation & purification*; Aspartic Acid Endopeptidases/metabolism
  11. Gangoda SVS, Avadhanam B, Jufri NF, Sohn EH, Butlin M, Gupta V, et al.
    Sci Rep, 2018 01 26;8(1):1689.
    PMID: 29374229 DOI: 10.1038/s41598-018-20117-6
    Amyloid β (Aβ) deposition is a hallmark of Alzheimer's disease (AD). Vascular modifications, including altered brain endothelial cell function and structural viability of the blood-brain barrier due to vascular pulsatility, are implicated in AD pathology. Pulsatility of phenomena in the cerebral vasculature are often not considered in in vitro models of the blood-brain barrier. We demonstrate, for the first time, that pulsatile stretch of brain vascular endothelial cells modulates amyloid precursor protein (APP) expression and the APP processing enzyme, β-secretase 1, eventuating increased-Aβ generation and secretion. Concurrent modulation of intercellular adhesion molecule 1 and endothelial nitric oxide synthase (eNOS) signaling (expression and phosphorylation of eNOS) in response to pulsatile stretch indicates parallel activation of endothelial inflammatory pathways. These findings mechanistically support vascular pulsatility contributing towards cerebral Aβ levels.
    Matched MeSH terms: Aspartic Acid Endopeptidases/analysis
  12. Sivasothy Y, Liew SY, Othman MA, Abdul Wahab SM, Hariono M, Mohd Nawi MS, et al.
    Trop Biomed, 2021 Jun 01;38(2):79-84.
    PMID: 33973577 DOI: 10.47665/tb.38.2.044
    The NS2B/NS3 protease is crucial for the pathogenesis of the DENV. Therefore, the inhibition of this protease is considered to be the key strategy for the development of new antiviral drugs. In the present study, malabaricones C (3) and E (4), acylphenols from the fruits of Myristica cinnamomea King, have been respectively identified as moderate (27.33 ± 5.45 μM) and potent (7.55 ± 1.64 μM) DENV-2 NS2B/NS3 protease inhibitors, thus making this the first report on the DENV-2 NS2B/NS3 protease inhibitory activity of acylphenols. Based on the molecular docking studies, compounds 3 and 4 both have π-π interactions with Tyr161. While compound 3 has hydrogen bonding interactions with Gly151, Gly153 and Tyr161, compound 4 however, forms hydrogen bonds with Ser135, Asp129, Phe130 and Ile86 instead. The results from the present study suggests that malabaricones C (3) and E (4) could be employed as lead compounds for the development of new dengue antivirals from natural origin.
    Matched MeSH terms: Endopeptidases
  13. Normah Ismail, Juliana Mahmod, Awatif Khairul Fatihin Mustafa Kamal
    MyJurnal
    In this study, Hydrolysate from angelwing clam (Pholas orientalis) was produced at 0, 1, 2 and 3 hrs and E/S ratio of 0.5 and 3% using alcalase where the pH and temperature were kept constant at pH 8.5 and 60°C, respectively. The hydrolysates were analysed for antioxidant and functional properties such as solubility, emulsifying properties and water and oil holding capacity. Degree of hydrolysis (DH), yield, functional and antioxidant properties were influenced by the hydrolysis time and E/S ratio. Higher enzyme concentration (E/S 3%) and longer hydrolysis time increased the DH. Yield was higher at E/S 3% but reduced with hydrolysis time. Longer hydrolysis time produced more soluble hydrolysate and higher metal chelating activity but lower in emulsifying properties and DPPH activity. Higher enzyme concentration resulted in increase only in solubility and metal chelating activity. This study revealed that enzymatic hydrolysis using alcalase should be performed at shorter hydrolysis time using intermediate concentration of enzyme (E/S between 0.5 to 3%) in order to produce angelwing clam hydrolysate with collectively good functional and antioxidant properties
    Matched MeSH terms: Endopeptidases
  14. Ghassem M, Fern SS, Said M, Ali ZM, Ibrahim S, Babji AS
    J Food Sci Technol, 2014 Mar;51(3):467-75.
    PMID: 24587521 DOI: 10.1007/s13197-011-0526-6
    This study was conducted to evaluate the kinetic characteristics of proteolytic activity of proteases on Channa striatus protein fractions. Degree of hydrolysis (DH), amino acid composition and kinetic parameters of sarcoplasmic and myofibrillar proteins were investigated when incubated with proteinase K and thermolysin, separately. After 30 min incubation with proteases, a decrease in DH of sarcoplasmic protein was observed whereas, hydrolysis of myofibrillar protein with proteases took 2 h with an increase in DH. The major amino acids were glutamic acid (16.6%) in thermolysin- myofibrillar hydrolysate followed by aspartic acid (11.1%) in sarcoplasmic protein fraction with no enzyme treatment and lysine (10%) in thermolysin-myofibrillar hydrolysate. The apparent Michaelis constant of proteinase K was lower than thermolysin for both sarcoplasmic and myofibrillar proteins. However, rate of turnover and enzyme efficiency suggested that sarcoplasmic and myofibrillar proteins are suitable substrates for proteinase K and thermolysin hydrolytic reaction, respectively.
    Matched MeSH terms: Endopeptidases
  15. Chang, S.K., Hamajima, H., Amin, I., Yanagita, T., Mohd. Esa, N., Baharuldin, M.T.H.
    MyJurnal
    This study was conducted to ascertain the cytotoxicity effect of oil palm (Elaeis guineensis) kernel protein hydrolysates (OPKHs) produced from its protein isolate. A modified microplate titer WST-1 [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium] assay was used to investigate the cytotoxicity of hydrolysates produced from protease and pepsin-pancreatin hydrolysis at various concentrations (0.1, 1, 10, 100 μg/ml and 1 mg/ml) using HepG2 cell model. Additionally, peptide stimulation test using OPKHs at 1 mg/ml was carried out to investigate whether OPKHs could serve as growth factor for HepG2 cells other than affecting its viability. As a result, oleic acid appeared to normalize the WST-1 readings of HepG2 cells treated with both hydrolysates at 1 mg/ml. The presence of amino acids in OPKHs could stimulate the growth and prolongs the viability of HepG2 cells. Both OPKHs were non-cytotoxic to HepG2 cells at all tested concentrations even at high concentrations. This study indicated that pepsin-pancreatin and protease hydrolysates produced from oil palm kernel protein were non-cytotoxic on HepG2 cells.
    Matched MeSH terms: Endopeptidases
  16. Ismail N, Ismail M, Azmi NH, Bakar MFA, Yida Z, Abdullah MA, et al.
    Biomed Pharmacother, 2017 Nov;95:780-788.
    PMID: 28892789 DOI: 10.1016/j.biopha.2017.08.074
    Though the causes of Alzheimer's disease (AD) are yet to be understood, much evidence has suggested that excessive amyloid-β (Aβ) accumulation due to abnormal amyloid-β precursor protein (APP) processing and Aβ metabolism are crucial processes towards AD pathogenesis. Hence, approaches aiming at APP processing and Aβ metabolism are currently being actively pursued for the management of AD. Studies suggest that high cholesterol and a high fat diet have harmful effects on cognitive function and may instigate the commencement of AD pathogenesis. Despite the neuropharmacological attributes of black cumin seed (Nigella sativa) extracts and its main active compound, thymoquinone (TQ), limited records are available in relation to AD research. Nanoemulsion (NE) is exploited as drug delivery systems due to their capacity of solubilising non-polar active compounds and is widely examined for brain targeting. Herewith, the effects of thymoquinone-rich fraction nanoemulsion (TQRFNE), thymoquinone nanoemulsion (TQNE) and their counterparts' conventional emulsion in response to high fat/cholesterol diet (HFCD)-induced rats were investigated. Particularly, the Aβ generation; APP processing, β-secretase 1 (BACE1), γ-secretases of presenilin 1 (PSEN1) and presenilin 2 (PSEN2), Aβ degradation; insulin degrading enzyme (IDE), Aβ transportation; low density lipoprotein receptor-related protein 1 (LRP1) and receptor for advanced glycation end products (RAGE) were measured in brain tissues. TQRFNE reduced the brain Aβ fragment length 1-40 and 1-42 (Aβ40 and Aβ42) levels, which would attenuate the AD pathogenesis. This reduction could be due to the modulation of β- and γ-secretase enzyme activity, and the Aβ degradation and transportation in/out of the brain. The findings show the mechanistic actions of TQRFNE in response to high fat and high cholesterol diet associated to Aβ generation, degradation and transportation in the rat's brain tissue.
    Matched MeSH terms: Aspartic Acid Endopeptidases/metabolism*
  17. Abusham RA, Rahman RN, Salleh AB, Basri M
    Microb Cell Fact, 2009 Apr 09;8:20.
    PMID: 19356254 DOI: 10.1186/1475-2859-8-20
    BACKGROUND: Many researchers have reported on the optimization of protease production; nevertheless, only a few have reported on the optimization of the production of organic solvent-tolerant proteases. Ironically, none has reported on thermostable organic solvent-tolerant protease to date. The aim of this study was to isolate the thermostable organic solvent-tolerant protease and identify the culture conditions which support its production. The bacteria of genus Bacillus are active producers of extra-cellular proteases, and the thermostability of enzyme production by Bacillus species has been well-studied by a number of researchers. In the present study, the Bacillus subtilis strain Rand was isolated from the contaminated soil found in Port Dickson, Malaysia.

    RESULTS: A thermostable organic solvent-tolerant protease producer had been identified as Bacillus subtilis strain Rand, based on the 16S rRNA analysis conducted, as well as the morphological characteristics and biochemical properties. The production of the thermostable organic solvent-tolerant protease was optimized by varying various physical culture conditions. Inoculation with 5.0% (v/v) of (AB600 = 0.5) inoculum size, in a culture medium (pH 7.0) and incubated for 24 h at 37 degrees C with 200 rpm shaking, was the best culture condition which resulted in the maximum growth and production of protease (444.7 U/ml; 4042.4 U/mg). The Rand protease was not only stable in the presence of organic solvents, but it also exhibited a higher activity than in the absence of organic solvent, except for pyridine which inhibited the protease activity. The enzyme retained 100, 99 and 80% of its initial activity, after the heat treatment for 30 min at 50, 55, and 60 degrees C, respectively.

    CONCLUSION: Strain Rand has been found to be able to secrete extra-cellular thermostable organic solvent-tolerant protease into the culture medium. The protease exhibited a remarkable stability towards temperature and organic solvent. This unique property makes it attractive and useful to be used in industrial applications.

    Matched MeSH terms: Endopeptidases
  18. Rahman RN, Mahamad S, Salleh AB, Basri M
    J Ind Microbiol Biotechnol, 2007 Jul;34(7):509-17.
    PMID: 17492323
    Five out of the nine benzene-toulene-ethylbenzene-xylene (BTEX) tolerant bacteria that demonstrated high protease activity on skim milk agar were isolated. Among them, isolate 115b identified as Bacillus pumilus exhibited the highest protease production. The protease produced was stable in 25% (v/v) benzene and toluene and it was activated 1.7 and 2.5- fold by n-dodecane and n-tetradecane, respectively. The gene encoding the organic solvent tolerant protease was cloned and its nucleotide sequence determined. Sequence analysis revealed an open reading frame (ORF) of 1,149 bp that encoded a polypeptide of 383 amino acid residues. The polypeptide composed of 29 residues of signal peptide, a propeptide of 79 residues and a mature protein of 275 amino acids with a calculated molecular mass of 27,846 Da. This is the only report available to date on organic solvent tolerant protease from B. pumilus.
    Matched MeSH terms: Endopeptidases/genetics; Endopeptidases/metabolism*; Endopeptidases/chemistry
  19. Latiffi AA, Salleh AB, Rahman RN, Oslan SN, Basri M
    Genes Genet Syst, 2013;88(2):85-91.
    PMID: 23832300
    The thermostable alkaline protease from Bacillus stearothermophilus F1 has high potential for industrial applications, and attempt to produce the enzyme in yeast for higher yield was undertaken. Secretory expression of F1 protease through yeast system could improve enzyme's capability, thus simplifying the purification steps. Mature and full genes of F1 protease were cloned into Pichia pastoris expression vectors (pGAPZαB and pPICZαB) and transformed into P. pastoris strains (GS115 and SMD1168H) via electroporation method. Recombinant F1 protease under regulation constitutive GAP promoter revealed that the highest expression was achieved after 72 h cultivation. While inducible AOX promoter showed that 0.5% (v/v) methanol was the best to induce expression. It was proven that constitutive expression strategy was better than inducible system. The α-secretion signal from the plasmid demonstrated higher secretory expression level of F1 protease as compared to native Open Reading Frame (ORF) in GS115 strain (GE6GS). Production medium YPTD was found to be the best for F1 protease expression with the highest yield of 4.13 U/mL. The protein was expressed as His-tagged fusion protein with a size about 34 kDa.
    Matched MeSH terms: Endopeptidases/genetics; Endopeptidases/secretion*
  20. Nuryastuti T, Henny C, Henk JB, Roel K, Abu TA, Bastiaan PK
    Med J Malaysia, 2008 Jul;63 Suppl A:97.
    PMID: 19025002
    Phenotypic variation in biofilm formation is common in clinical isolates of S. epidermidis. In the current study, nearly 5% of all clinical isolates analysed showed phenotypic variation in biofilm forming ability and electrophoretic mobility (EM). This is the first report of S. epidermidis strains irreversibly switching from biofilm-positive to biofilm-negative phenotype by spontaneous deletion of icaADBC genes which represents a new, possibly common mechanism of phenotypic variation.
    Matched MeSH terms: Serine Endopeptidases/genetics; Serine Endopeptidases/metabolism
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