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An overview of antifungal peptides derived from insect

Faruck MO, Yusof F, Chowdhury S

Peptides, 2016 06;80:80-88.
PMID: 26093218 DOI: 10.1016/j.peptides.2015.06.001

Fungi are not classified as plants or animals. They resemble plants in many ways but do not produce chlorophyll or make their own food photosynthetically like plants. Fungi are useful for the production of beer, bread, medicine, etc. More complex than viruses or bacteria; fungi can be destructive human pathogens responsible for various diseases in humans. Most people have a strong natural immunity against fungal infection. However, fungi can cause diseases when this immunity breaks down. In the last few years, fungal infection has increased strikingly and has been accompanied by a rise in the number of deaths of cancer patients, transplant recipients, and acquired immunodeficiency syndrome (AIDS) patients owing to fungal infections. The growth rate of fungi is very slow and quite difficult to identify. A series of molecules with antifungal activity against different strains of fungi have been found in insects, which can be of great importance to tackle human diseases. Insects secrete such compounds, which can be peptides, as a part of their immune defense reactions. Active antifungal peptides developed by insects to rapidly eliminate infectious pathogens are considered a component of the defense munitions. This review focuses on naturally occurring antifungal peptides from insects and their challenges to be used as armaments against human diseases.

Matched MeSH terms: Peptides/pharmacology; Peptides/chemistry
Fulltext Novel angiotensin I-converting enzyme inhibitory peptides derived from an edible mushroom, Pleurotus cystidiosus O.K. Miller identified by LC-MS/MS

Lau CC, Abdullah N, Shuib AS

BMC Complement Altern Med, 2013 Nov 11;13:313.
PMID: 24215325 DOI: 10.1186/1472-6882-13-313

BACKGROUND: Angiotensin I-converting enzyme (ACE) inhibitors have been reported to reduce mortality in patients with hypertension. Compared to chemosynthetic drugs, ACE inhibitors derived from natural sources such as food proteins are believed to be safer for consumption and to have fewer adverse effects. Some edible mushrooms have been reported to significantly reduce blood pressure after oral administration. In addition, mushrooms are known to be rich in protein content. This makes them a potential source of ACE inhibitory peptides. Hence, the objective of the current study was to isolate and characterise ACE inhibitory peptides from an edible mushroom, Pleurotus cystidiosus.
METHODS: ACE inhibitory proteins were isolated from P. cystidiosus based on the bioassay guided purification steps, i.e. ammonium sulphate precipitation, reverse phase high performance liquid chromatography and size exclusion chromatography. Active fraction was then analysed by LC-MS/MS and potential ACE inhibitory peptides identified were chemically synthesized. Effect of in vitro gastrointestinal digestions on the ACE inhibitory activity of the peptides and their inhibition patterns were evaluated.
RESULTS: Two potential ACE inhibitory peptides, AHEPVK and GPSMR were identified from P. cystidiosus with molecular masses of 679.53 and 546.36 Da, respectively. Both peptides exhibited potentially high ACE inhibitory activity with IC50 values of 62.8 and 277.5 μM, respectively. SEC chromatograms and BIOPEP analysis of these peptides revealed that the peptide sequence of the hexapeptide, AHEPVK, was stable throughout gastrointestinal digestion. The pentapeptide, GPSMR, was hydrolysed after digestion and it was predicted to release a dipeptide ACE inhibitor, GP, from its precursor. The Lineweaver-Burk plot of AHEPVK showed that this potent and stable ACE inhibitor has a competitive inhibitory effect against ACE.
CONCLUSION: The present study indicated that the peptides from P. cystidiosus could be potential ACE inhibitors. Although these peptides had lower ACE inhibitory activity compared to commercial antihypertensive drugs, they are derived from mushroom which could be easily obtained and should have no side effects. Further in vivo studies can be carried out to reveal the clear mechanism of ACE inhibition by these peptides.

Matched MeSH terms: Peptides/isolation & purification; Peptides/chemistry*
Extraction of antioxidative and antihypertensive bioactive peptides from Parkia speciosa seeds

Siow HL, Gan CY

Food Chem, 2013 Dec 15;141(4):3435-42.
PMID: 23993504 DOI: 10.1016/j.foodchem.2013.06.030

Antioxidative and antihypertensive bioactive peptides were successfully derived from Parkia speciosa seed using alcalase. The effects of temperature (25 and 50 °C), substrate-to-enzyme ratio (S/E ratio, 20 and 50), and incubation time (0.5, 1, 2 and 5h) were evaluated based on 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and angiotensin-converting enzyme (ACE) assays. Bioactive peptide extracted at a hydrolysis condition of: temperature=50 °C, S/E ratio=50 and incubation time=2h, exhibited the highest DPPH radical scavenging activity (2.9 mg GAE/g), reducing power (11.7 mM) and %ACE-inhibitory activity (80.2%). The sample was subsequently subjected to fractionation and the peptide fraction of <10 kDa showed the strongest bioactivities. A total of 29 peptide sequences from peptide fraction of <10 kDa were identified as the most potent contributors to the bioactivities. These novel bioactive peptides were suggested to be beneficial to nutraceutical and food industries.

Matched MeSH terms: Peptides/isolation & purification; Peptides/chemistry*
Lymph node metastasis of primary endometrial cancers: Associated proteins revealed by MALDI imaging

Mittal P, Klingler-Hoffmann M, Arentz G, Winderbaum L, Lokman NA, Zhang C, et al.

Proteomics, 2016 06;16(11-12):1793-801.
PMID: 27061135 DOI: 10.1002/pmic.201500455

Metastasis is a crucial step of malignant progression and is the primary cause of death from endometrial cancer. However, clinicians presently face the challenge that conventional surgical-pathological variables, such as tumour size, depth of myometrial invasion, histological grade, lymphovascular space invasion or radiological imaging are unable to predict with accuracy if the primary tumour has metastasized. In the current retrospective study, we have used primary tumour samples of endometrial cancer patients diagnosed with (n = 16) and without (n = 27) lymph node metastasis to identify potential discriminators. Using peptide matrix assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI), we have identified m/z values which can classify 88% of all tumours correctly. The top discriminative m/z values were identified using a combination of in situ sequencing and LC-MS/MS from digested tumour samples. Two of the proteins identified, plectin and α-Actin-2, were used for validation studies using LC-MS/MS data independent analysis (DIA) and immunohistochemistry. In summary, MALDI-MSI has the potential to identify discriminators of metastasis using primary tumour samples.

Matched MeSH terms: Peptides/genetics; Peptides/isolation & purification*
Fulltext Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Oxidant Activities of Sea Cucumber (Actinopyga lecanora) Hydrolysates

Ghanbari R, Zarei M, Ebrahimpour A, Abdul-Hamid A, Ismail A, Saari N

Int J Mol Sci, 2015 Dec 04;16(12):28870-85.
PMID: 26690117 DOI: 10.3390/ijms161226140

In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora) hydrolysates, which had been prepared by alcalase, papain, bromelain, flavourzyme, pepsin, and trypsin under their optimum conditions. The alcalase hydrolysate showed the highest ACE inhibitory activity (69.8%) after 8 h of hydrolysis while the highest anti-oxidative activities measured by 2,2-diphenyl 1-1-picrylhydrazyl radical scavenging (DPPH) (56.00%) and ferrous ion-chelating (FIC) (59.00%) methods were exhibited after 24 h and 8 h of hydrolysis, respectively. The ACE-inhibitory and anti-oxidative activities displayed dose-dependent trends, and increased with increasing protein hydrolysate concentrations. Moreover, strong positive correlations between angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities were also observed. This study indicates that A. lecanora hydrolysate can be exploited as a source of functional food owing to its anti-oxidant as well as anti-hypertension functions.

Matched MeSH terms: Peptides/pharmacology; Peptides/chemistry
Anti-dengue virus serotype 2 activity and mode of action of a novel peptide

Chew MF, Tham HW, Rajik M, Sharifah SH

J Appl Microbiol, 2015 Oct;119(4):1170-80.
PMID: 26248692 DOI: 10.1111/jam.12921

To identify a novel antiviral peptide against dengue virus serotype 2 (DENV-2) by screening a phage display peptide library and to evaluate its in vitro antiviral activity and mode of action.

Matched MeSH terms: Peptides/pharmacology*; Peptides/chemistry
Bactericidal and fungistatic activity of peptide derived from GH18 domain of prawn chitinase 3 and its immunological functions during biological stress

Ravichandran G, Kumaresan V, Mahesh A, Dhayalan A, Arshad A, Arasu MV, et al.

Int J Biol Macromol, 2018 Jan;106:1014-1022.
PMID: 28837852 DOI: 10.1016/j.ijbiomac.2017.08.098

Chitinases play a vital role during the pathogenic invasion and immunosuppression in various organisms including invertebrates and vertebrates. In this study, we have investigated the participation of MrChit-3 (Macrobrachium rosenbergii Chitinase-3) during host-pathogenic interaction in freshwater prawn, M. rosenbergii. Quantitative real-time PCR analysis showed that the expression of MrChit-3 was up-regulated during bacterial, viral and laminarin challenge. Moreover, to understand the antimicrobial role of the GH18 domain, a putative membrane-targeting antimicrobial peptide (MrVG) was identified from the GH18 domain region of the protein and it was chemically synthesized. Physico-chemical features of the GH18 derived antimicrobial peptide (AMP) was assessed by various in silico tools and the antimicrobial property of the peptide was confirmed from in vitro studies. The membrane targeting mechanism of the peptide was determined by flow cytometry (FACS) and scanning electron microscope (SEM) analysis. Interestingly, the peptide was able to inhibit the growth of a chitinolytic fungal pathogen, Aspergillus niger, which was isolated from the shells of M. rosenbergii. The toxicity studies such as hemolysis activity on human blood erythrocytes and cell viability assay with primary kidney cells, HEK293 of MrVG revealed that the peptide was not involved in inducing any toxicity.

Matched MeSH terms: Antimicrobial Cationic Peptides/genetics; Antimicrobial Cationic Peptides/pharmacology*; Antimicrobial Cationic Peptides/chemistry
Controversies in the vascular theory of glaucomatous optic nerve degeneration

Ahmad SS

Taiwan J Ophthalmol, 2016 Oct-Dec;6(4):182-186.
PMID: 29018738 DOI: 10.1016/j.tjo.2016.05.009

An understanding of the pathogenesis of glaucoma is one of the foundations in glaucoma management. A number of theories have been presented to explain glaucomatous neural degeneration. The vascular theory attempts to explain the causation of glaucoma on the basis of vasogenic factors and altered he-modynamics in the body; however, this theory remains controversial. There are proponents for and against the role played by vascular factors in the development of glaucomatous optic nerve degeneration. This review aims to analyze the various studies performed to provide evidence for and against the vascular theory of glaucoma. It also affirms the need to undertake further studies regarding the path-ogenesis of glaucoma and integrate them into our management strategies. The literature search for this systemic analysis was performed using search engines, such as PubMed, The Virtual Library of the Ministry of Health Malaysia, Google Scholar, and ClinicalKey.

Matched MeSH terms: Peptides
Fulltext Complete genome of Arthrobacter alpinus strain R3.8, bioremediation potential unraveled with genomic analysis

See-Too WS, Ee R, Lim YL, Convey P, Pearce DA, Mohidin TBM, et al.

Stand Genomic Sci, 2017;12:52.
PMID: 28904741 DOI: 10.1186/s40793-017-0264-0

Arthrobacter alpinus R3.8 is a psychrotolerant bacterial strain isolated from a soil sample obtained at Rothera Point, Adelaide Island, close to the Antarctic Peninsula. Strain R3.8 was sequenced in order to help discover potential cold active enzymes with biotechnological applications. Genome analysis identified various cold adaptation genes including some coding for anti-freeze proteins and cold-shock proteins, genes involved in bioremediation of xenobiotic compounds including naphthalene, and genes with chitinolytic and N-acetylglucosamine utilization properties and also plant-growth-influencing properties. In this genome report, we present a complete genome sequence of A. alpinus strain R3.8 and its annotation data, which will facilitate exploitation of potential novel cold-active enzymes.

Matched MeSH terms: Cold Shock Proteins and Peptides
Fulltext Optimization of the enzymatic hydrolysis conditions of waste from shortfin scad (Decapterus Macrosoma) for the production of angiotensin I-converting enzyme (ACE) inhibitory peptide using response surface methodology

Ishak, N.H., Sarbon, N.M.

International Food Research Journal, 2017;24(4):1735-1743.
MyJurnal

This study aims to optimize enzymatic hydrolysis process for producing angiotensin I-converting enzyme (ACE) inhibitory peptides from protein hydrolysate of shortfin scad (Decapterus Macrosoma) waste (SWH). The enzymatic hydrolysis conditions, namely the temperature (40, 50, 60°C), time (B: 60, 120, 180 min), pH (C: 7, 8, 9) and enzyme substrate concentrations (D: 1, 2, 3%) on yield, degree of hydrolysis (DH) and ACE-inhibitory activity were analysed. Responses were optimized using the response surface methodology (RSM) by employing four factors, 3-levels and the Central Composite Design (CCD). The optimized conditions were further validated to indicate the validity of the prediction model. The optimal conditions obtained for the hydrolysis conditions were at temperature of 50°C, time of 60 min, pH of 9 and enzyme to substrate concentration of 2.92%. The experimental result for yield was lower than the predicted value, as generated by RSM. However, the degree of hydrolysis of SWH was higher than the predicted value. The ACE inhibitory activity of SWH was 79.34%, and showed lower than the predicted value. Therefore, the optimized conditions of SWH served as good conditions for the production of bioactive peptide with high ACE inhibitory activity.

Matched MeSH terms: Peptides
Design and tuning of a cell-penetrating albumin derivative as a versatile nanovehicle for intracellular drug delivery

Ichimizu S, Watanabe H, Maeda H, Hamasaki K, Nakamura Y, Chuang VTG, et al.

J Control Release, 2018 05 10;277:23-34.
PMID: 29530390 DOI: 10.1016/j.jconrel.2018.02.037

Human serum albumin (HSA) is a superior carrier for delivering extracellular drugs. However, the development of a cell-penetrating HSA remains a great challenge due to its low membrane permeability. We report herein on the design of a series of palmitoyl-poly-arginine peptides (CPPs) and an evaluation of their cell-penetrating effects after forming a complex with HSA for use in intracellular drug delivery. The palmitoyl CPPs forms a stable complex with HSA by anchoring itself to the high affinity palmitate binding sites of HSA. Among the CPPs evaluated, a cyclic polypeptide composed of D-dodecaarginines, palmitoyl-cyclic-(D-Arg)12 was the most effective for facilitating the cellular uptake of HSA by HeLa cells. Such a superior cell-penetrating capability is primarily mediated by macropinocytosis. The effect of the CPP on pharmacological activity was examined using three drugs loaded in HSA via three different methods: a) an HSA-paclitaxel complex, b) an HSA-doxorubicin covalent conjugate and c) an HSA-thioredoxin fusion protein. The results showed that cell-penetrating efficiency was increased with a corresponding and significant enhancement in pharmacological activity. In conclusion, palmitoyl-cyclic-(D-Arg)12/HSA is a versatile cell-penetrating drug delivery system with great potential for use as a nano-carrier for a wide diversity of pharmaceutical applications.

Matched MeSH terms: Cell-Penetrating Peptides/administration & dosage*; Cell-Penetrating Peptides/chemical synthesis; Cell-Penetrating Peptides/metabolism
Fulltext Peptidomics dataset: Blood plasma and serum samples of healthy donors fractionated on a set of chromatography sorbents

Arapidi G, Osetrova M, Ivanova O, Butenko I, Saveleva T, Pavlovich P, et al.

Data Brief, 2018 Jun;18:1204-1211.
PMID: 29900295 DOI: 10.1016/j.dib.2018.04.018

Blood as connective tissue potentially contains evidence of all processes occurring within the organism, at least in trace amounts (Petricoin et al., 2006) [1]. Because of their small size, peptides penetrate cell membranes and epithelial barriers more freely than proteins. Among the peptides found in blood, there are both fragments of proteins secreted by various tissues and performing their function in plasma and receptor ligands: hormones, cytokines and mediators of cellular response (Anderson et al., 2002) [2]. In addition, in minor amounts, there are peptide disease markers (for example, oncomarkers) and even foreign peptides related to pathogenic organisms and infection agents. To propose an approach for detailed peptidome characterization, we carried out an LC-MS/MS analysis of blood serum and plasma samples taken from 20 healthy donors on a TripleTOF 5600+ mass-spectrometer. We prepared samples based on our previously developed method of peptide desorption from the surface of abundant blood plasma proteins followed by standard chromatographic steps (Ziganshin et al., 2011) [3]. The mass-spectrometry peptidomics data presented in this article have been deposited to the ProteomeXchange Consortium (Deutsch et al., 2017) [4] via the PRIDE partner repository with the dataset identifier PXD008141 and 10.6019/PXD008141.

Matched MeSH terms: Peptides
Fulltext The endogenous antimicrobial cathelicidin LL37 induces platelet activation and augments thrombus formation

Salamah MF, Ravishankar D, Kodji X, Moraes LA, Williams HF, Vallance TM, et al.

Blood Adv, 2018 Nov 13;2(21):2973-2985.
PMID: 30413433 DOI: 10.1182/bloodadvances.2018021758

Platelet-associated complications including thrombosis, thrombocytopenia, and hemorrhage are commonly observed during various inflammatory diseases such as sepsis, inflammatory bowel disease, and psoriasis. Despite the reported evidence on numerous mechanisms/molecules that may contribute to the dysfunction of platelets, the primary mechanisms that underpin platelet-associated complications during inflammatory diseases are not fully established. Here, we report the discovery of formyl peptide receptor 2, FPR2/ALX, in platelets and its primary role in the development of platelet-associated complications via ligation with its ligand, LL37. LL37 acts as a powerful endogenous antimicrobial peptide, but it also regulates innate immune responses. We demonstrate the impact of LL37 in the modulation of platelet reactivity, hemostasis, and thrombosis. LL37 activates a range of platelet functions, enhances thrombus formation, and shortens the tail bleeding time in mice. By utilizing a pharmacological inhibitor and Fpr2/3 (an ortholog of human FPR2/ALX)-deficient mice, the functional dependence of LL37 on FPR2/ALX was determined. Because the level of LL37 is increased in numerous inflammatory diseases, these results point toward a critical role for LL37 and FPR2/ALX in the development of platelet-related complications in such diseases. Hence, a better understanding of the clinical relevance of LL37 and FPR2/ALX in diverse pathophysiological settings will pave the way for the development of improved therapeutic strategies for a range of thromboinflammatory diseases.

Matched MeSH terms: Antimicrobial Cationic Peptides/metabolism; Antimicrobial Cationic Peptides/pharmacology*; Antimicrobial Cationic Peptides/chemistry
Fulltext Mechanical and physical properties of gellan gum (GG) biofilm: effect of glycerol

Razali, M.H., Ismail, N.A., Osman, U.M., Amin, K.A.M.

ASM Science Journal, 2018;11(101):158-165.
MyJurnal

The aim of this work was to investigate the effect of glycerol concentration on mechanical
and physical properties of gellan gum (GG) biofilm. The biofilm was prepared using solvent
casting method and the effective glycerol concentration was found to be within 30-50%
w/w (based on GG weight). At 60 and 70 w/w% of glycerol, the films started to distort
because the films was flexible and brittle. As glycerol concentration was increased the tensile
strength (TS) and Youngs modulus (E) of films decreased. Somehow, elongation at break
(EAB), water vapor transmission rate (WVTR) and swelling of films was increased. Glycerol
plasticized GG biofilm was thermally stable and flexible, proposed its can be exploited as
film-forming material and with optimized glycerol concentration it has good mechanical and
physical properties for edible biofilm.

Matched MeSH terms: Intracellular Signaling Peptides and Proteins
Fulltext The modified Gompertz model demonstrates a variable growth rate between two Centella asiatica phenotypes

Hussein, S., Halmi, M.I.E., Ling, A.P.K.

Journal of Biochemistry, Microbiology and Biotechnology, 2017;5(1):18-20.
MyJurnal

Centella asiatica, a weakly aromatic plant that flourishes in wet tropical and sub-tropical areas as
a medicinal species since ancient times. It contained important terpenoids that impart important
medicinal values. Currently, studies on the terpenoid content of various Centella asiatica
phenotypes have shown not only variable content but variable growth rates of different
phenotypes that can affect future selection of phenotypes. The use of mathematical growth
modelling can reveal important growth constants and discriminate between faster and slower
growth phenotypes. Two Centella asiatica phenotypes from South Africa is modelled using the
modified Gompertz model and the results showed that the C. asiatica Type-1 exhibited a faster
growth rates and a shorter lag period at 0.152 day-1 and 2.313 day than another phenotype; C.
asiatica Type 2 with a growth rate and a lag period of 0.067 day-1 and 3.363 day, respectively.
The data indicates that different phenotypes of C. asiatica can have different growth rates and
lag period and this can be important for selection of phenotypes to be used as the best bioactive
peptides producer.

Matched MeSH terms: Peptides
Curcumin and a hemi-analogue with improved blood-brain barrier permeability protect against amyloid-beta toxicity in Caenorhabditis elegans via SKN-1/Nrf activation

Lee EH, Lim SS, Yuen KH, Lee CY

J Pharm Pharmacol, 2019 May;71(5):860-868.
PMID: 30515807 DOI: 10.1111/jphp.13052

OBJECTIVES: This study aims to investigate the blood-brain barrier (BBB) permeability of curcumin analogues with shortened linkers and their ability to protect against amyloid-beta toxicity in a whole organism model.
METHOD: Four curcumin analogues were synthesized. These analogues and curcumin were evaluated for their BBB permeability in the parallel artificial membrane permeability assay. The transgenic Caenorhabditis elegansGMC101 that expresses human Aβ1-42 was treated with the compounds to evaluate their ability to delay Aβ-induced paralysis. Expression of skn-1mRNA was examined on nematodes treated with selected efficacious compounds. In vitro Aβ aggregation in the presence of the compounds was performed.
KEY FINDINGS: The four analogues showed improved BBB permeability vs curcumin in the PAMPA with the hemi-analogue C4 having the highest permeability coefficient. At 100 μm, analogues C1 and C4 as well as curcumin significantly prolonged the survival of the nematodes protecting against Aβ toxicity. However, only curcumin and C4 showed protection at lower concentrations. skn-1mRNA was significantly elevated in nematodes treated with curcumin and C4 indicating SKN-1/Nrf activation as a possible mode of action.
CONCLUSIONS: Analogue C4 provides a new lead for the development of a curcumin-based compound for protection against Aβ toxicity with an improved BBB permeability.

Matched MeSH terms: Amyloid beta-Peptides
Elastic reversible valves on centrifugal microfluidic platforms

Aeinehvand MM, Weber L, Jiménez M, Palermo A, Bauer M, Loeffler FF, et al.

Lab Chip, 2019 Feb 20.
PMID: 30785443 DOI: 10.1039/c8lc00849c

Reversible valves on centrifugal microfluidic platforms facilitate the automation of bioanalytical assays, especially of those requiring a series of steps (such as incubation) in a single reaction chamber. In this study, we present fixed elastic reversible (FER) valves and tunable elastic reversible (TER) valves that are easy to fabricate, implement and control. In the FER valve the compression of an elastic barrier/patch against a microchamber's outlet prevents the release of liquid. The valve sealing pressure was determined by adjusting the engraving depth of the valve-seat at which the elastic patch was located, this allows to set the sealing pressure during disc fabrication. In the TER valve, the patch compression value and sealing pressure is controlled by the penetration depth of a plastic screw into the valve-seat. The ER valves prevent liquid flow until the centrifugal force overcomes their sealing pressure. Moreover, at a constant spin speed, turning the screw of a TER valve reduces its sealing pressure and opens the valve. Therefore, the TER valve allows for controlling of the liquid transfer volume at various spin speeds. The FER and TER valves' behavior is mathematically described and equations for the prediction of their operation under centrifugal forces are provided. As a point-of-care (POC) application of ER valves, we have developed a microfluidic disc with a series of TER valves and peptide microarrays for automated multiplexed detection of five different proteins from a single serum sample.

Matched MeSH terms: Peptides
Fulltext The epidermal mucus extract of clarias batrachus inhibits gram negative bacteria growth

Ahmad Zorin Sahalan, Engku Sharmila, Nazahiyah Sulaiman

Jurnal Sains Kesihatan Malaysia, 2018;16(101):83-87.
MyJurnal

Recently, epidermal mucus of fish has been identified as a rich biological source of various bioactive substances, particularly antibacterial peptides. This study was conducted to identify the potential of epidermal mucosa of Clarias batrachus as a source of antibacterial material. Mucosal samples were collected from C. batrachus epidermis and extracted using an aqueous extraction method. Antibacterial activity of the crude epidermal mucus extract was determined by using spectrophotometric method. As a result there was antibacterial activity by the mucus extract against Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853). The results of this study supports the role of mucus as a part of body immune system with antibacterial peptide as a component of innate body immune system. Hence, these findings can be used as one of the first steps towards the development of new class antibiotics.

Matched MeSH terms: Peptides
Tuning the optical band gap of DH6T by Alq3 dopant

Fahmi Fariq Muhammad, Khaulah Sulaiman

Sains Malaysiana, 2011;40.

Dihexyl-sexithiophene (DH6T) was doped with tris (8-hydroxyquinolinate) aluminum (Alq3) to prepare blends of DH6T/ Alq3 by dissolving the mixture in the chloroform/hexane co-solvent. Solid films with different thickness deposited on quartz substrates were obtained from the blends via casting process. Optical absorption spectroscopy has been performed to measure the optical band gap of pure and doped DH6T as well as variations in the band gap with dopant concentration (weight %). This variation in optical band gap with dopant concentration was determined quantitatively with fitted and extrapolated techniques and observed qualitatively from the red shift appeared along the optical absorption spectra. The results showed that within a specific dopant content, the optical energy gap, Eg of DH6T decreases from 2.69 eV to 1.8 eV with increasing dopant concentration to 23.1%.

Matched MeSH terms: Intracellular Signaling Peptides and Proteins
Pressure sensitive organic sensor based on CNT-V02 (3fl) composite

Khan A, Karimov KS, Zubair Armad, Khaulah Sulaiman, Shah M, Moiz S

Sains Malaysiana, 2014;43:903-908.

In this paper, fabrication and investigation of organic pressure sensor based on AlICIVT-VO 2(3j7)ICu composite is reported. The active layer of the composite was deposited by drop-casting of the blend CN'T-VO 2 (3fl) on a glass substrate (with prefabricated copper (Cu) electrode). The thin film of the blend consists of carbon nanotube CNT, (2.55 wt. %) and vanadium oxide (VO 2 (3fl)) micropowder, (3 wt. %) in benzol (1 mL). The thickness of the composite was in the range of 20-40 ,um. It was found that the fabricated sensor was sensitive to pressure and showed good repeatability. The decrease in resistance of the sensor was observed by increasing the external uniaxial pressure up to 50 kNm-2 . The experimentally obtained results were compared with the simulated results and showed reasonable agreement with each other.

Matched MeSH terms: Intracellular Signaling Peptides and Proteins

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