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Epinecidin-1, a marine antifungal peptide, inhibits Botrytis cinerea and delays gray mold in postharvest peaches

Fan L, Wei Y, Chen Y, Jiang S, Xu F, Zhang C, et al.

Food Chem, 2023 Mar 01;403:134419.
PMID: 36191421 DOI: 10.1016/j.foodchem.2022.134419

This study investigatedthe mechanism of epinecidin-1 against Botrytis cinerea, in vitro, and its effectiveness at inhibiting gray mold on postharvest peach fruit. We found that in vitro, epinecidin-1 had significantly greater antifungal activity against B. cinerea than either clavanin-A or mytimycin, two other marine derived antimicrobial peptides that we tested. Its antifungal activity was heat-resistant (15 min at 40-100 °C) and tolerant to lower concentrations of cations (<100 mM Na+, K+; <10 mM Ca2+). Epinecidin-1 interacted directly with B. cinerea genomic DNA, and that in mycelia, epinecidin-1 exposure induced accumulation of intracellular ROS and increased the permeability of cell membranes resulting in leakage of nucleic acids and aberrant cell morphology. Meanwhile, 200 μM of epinecidin-1 had a significant inhibitory effect on gray mold injected into peach fruit. These results suggested that epinecidin-1 showed promise as a potential method for controlling postharvest gray mold in peaches.

Matched MeSH terms: Peptides/pharmacology
Electrochemical biosensor for trypsin activity assay based on cleavage of immobilized tyrosine-containing peptide

Filippova TA, Masamrekh RA, Shumyantseva VV, Latsis IA, Farafonova TE, Ilina IY, et al.

Talanta, 2023 May 15;257:124341.
PMID: 36821964 DOI: 10.1016/j.talanta.2023.124341

In this work, we proposed a biosensor for trypsin proteolytic activity assay using immobilization of model peptides on screen-printed electrodes (SPE) modified with gold nanoparticles (AuNPs) prepared by electrosynthetic method. Sensing of proteolytic activity was based on electrochemical oxidation of tyrosine residues of peptides. We designed peptides containing N-terminal cysteine residue for immobilization on an SPE, modified with gold nanoparticles, trypsin-specific cleavage site and tyrosine residue as a redox label. The peptides were immobilized on SPE by formation of chemical bonds between mercapto groups of the N-terminal cysteine residues and AuNPs. After the incubation with trypsin, time-dependent cleavage of the immobilized peptides was observed by decline in tyrosine electrochemical oxidation signal. The kinetic parameters of trypsin, such as the catalytic constant (kcat), the Michaelis constant (KM) and the catalytic efficiency (kcat/KM), toward the CGGGRYR peptide were determined as 0.33 ± 0.01 min-1, 198 ± 24 nM and 0.0016 min-1 nM-1, respectively. Using the developed biosensor, we demonstrated the possibility of analysis of trypsin specificity toward the peptides with amino acid residues disrupting proteolysis. Further, we designed the peptides with proline or glutamic acid residues after the cleavage site (CGGRPYR and CGGREYR), and trypsin had reduced activity toward both of them according to the existing knowledge of the enzyme specificity. The developed biosensor system allows one to perform a comparative analysis of the protease steady-state kinetic parameters and specificity toward model peptides with different amino acid sequences.

Matched MeSH terms: Peptides/chemistry
The clinical assessment of changes in bone density in rheumatoid arthritis patients': Role of DEXA scan and bone turnover biomarkers

Al-Bogami MM, Alkhorayef M, Sulieman A, Bradley D, Jawad AS, Mageed RA

Appl Radiat Isot, 2024 Sep;211:111373.
PMID: 38851075 DOI: 10.1016/j.apradiso.2024.111373

In addition to generalised of bone loss and a higher fracture risk, rheumatoid arthritis (RA) causes periarticular bone erosions. Improvements in bone density/erosion and turnover may not go hand in hand with a positive clinical response to biological anti-inflammatory drugs assesed by disease activity score 28 (DAS28) in RA patients. This study aimed to understand how biologic anti-inflammatory drugs affect bone density, erosion, and turnover in RA patients. We examined bone mineral density (BMD) and bone turnover biomarkers. The study population consisted of 62 RA patients, 49 (79%) of whom were female and 13 (21%) of whom were male. The patients ranged in age from 40 to 79 years old. The patients' BMD was measured using a DEXA scan, and their plasma levels of bone turnover biomarkers CTX and osteocalcin were quantified utilizing an ELISA. BMD of the hip and lumbar spine in responder patients rose after therapy by 0.001g/cm2 (0.11 percent, p0.001 vs. before treatment) and 0.0396g/cm2 (3.96 percent, p0.001 vs. before treatment), respectively. Clinically non-responder patients' DAS28 revealed minor reductions in hip BMD values of -0.008g/cm2 (-0.78 percent, p0.001 vs. before therapy), as well as an improvement in lumbar spine BMD of 0.03g/cm2 (3.03 percent, p0.001 vs. before treatment). After 12 weeks of therapy, the CTX levels in responder patients dropped from 164 125 pg/ml to 131 129 pg/ml. Osteocalcin levels in non-responder patients increased substantially from 11.6 ng/ml to 14.9 ng/ml after 12 weeks of therapy compared to baseline (p = 0.01). Treatment with biologic anti-inflammatory medicines decreases widespread bone loss in RA patients' hip and lumbar spine. The beneficial effects of therapy on BMD were not associated with changes in disease activity of RA patients. Changes in plasma levels of bone turnover biomarkers such as sCTX and osteocalcin confirmed the treatment's beneficial effects.

Matched MeSH terms: Peptides/blood
Biomarkers

Yanagisawa D, Arrozi AP, Kato T, Mizukami T, Akatsu H, Yoshio H, et al.

Alzheimers Dement, 2024 Dec;20 Suppl 2(Suppl 2):e084341.
PMID: 39786169 DOI: 10.1002/alz.084341

BACKGROUND: Abnormal protein depositions of amyloid β and tau are present in the nasal cavity in patients with Alzheimer's disease. This finding raises an idea that nasal tissues would be a promising source of diagnostic biomarkers for Alzheimer's disease. However, the amounts of amyloid β and tau are extremely small, making it difficult to quantify the levels using conventional methods such as ELISA, and thus it is challenging to utilize them for the diagnostic biomarkers. In the present study, we tested the nasal tissues as the source of diagnostic biomarkers using a cellular model of tau propagation.
METHOD: This study was approved by the institutional Ethics Committees. Postmortem nasal mucosa and brain tissues from patients with AD (n = 10) and normal subjects (n = 10) were collected with patient consent at the Fukushimura Brain Bank. Nasal and brain tissue homogenates were added to HEK293 cells expressing tau 3-repeat domain with the L266V and V337M mutations (3RD∗VM) or 4-repeat domain with the P301L and V337M mutations (4RD∗LM), which was fused with GFP at the C-terminus.
RESULT: GFP fluorescence was detected uniformly within the cell bodies of HEK293T cells expressing 3RD∗VM-EGFP and 4RD∗LM-EGFP. There were no changes in the fluorescence after the additions of the brain homogenates from normal subjects. In contrast, a large number of fluorescent puncta was detected both in HEK293T cells expressing 3RD∗VM-EGFP and 4RD∗LM-EGFP at 4 days after the additions of the brain homogenates from patients with AD. Furthermore, the nasal tissue homogenates from patients with AD also induce the formation of fluorescent aggregates in HEK293T cells expressing 3RD∗VM-EGFP and 4RD∗LM-EGFP. Quantitative analysis revealed that the nasal tissue homogenates from AD patients significantly induced the aggregate formation, compared with normal subjects.
CONCLUSION: These results suggest that the nasal tissues from AD patients contain tau seeds with prion activity, similar to the brain. A cellular bioassay using nasal tissues would be great potential as an AD biomarker because of the usefulness of nasal tissue biopsy, and would provide an important contribution to the development of ex vivo diagnosis method for AD using the nasal extracts.

Matched MeSH terms: Amyloid beta-Peptides/metabolism
The mechanism underlying streptozotocin injection for the development of a nontransgenic Alzheimer's disease animal model

Titisari N, Ahmad H, Samsulrizal N, Fauzi A, Abdul Razak IS

Open Vet J, 2025 Feb;15(2):594-600.
PMID: 40201829 DOI: 10.5455/OVJ.2025.v15.i2.8

Streptozotocin (STZ) is a widely used chemical agent in biomedical research. It is primarily known for its ability to induce high blood glucose levels in animal models by selectively destroying pancreatic beta cells. Nonetheless, many studies have also used STZ to generate animal models of diabetic complications, such as Alzheimer's disease (AD) animal models. STZ induction promotes hyperglycemia, which activates numerous mechanism pathways that result in the production of pathogenic AD characteristics, including beta-amyloid accumulation and neurofibrillary tangles. Numerous theories exist to elucidate the mechanisms underlying diabetes and AD; however, studies on the potential of an animal model of STZ-induced AD remain limited. Thus, this review summarizes the pathogenesis associated with STZ exposure, particularly in AD animal model studies related to diabetes. More specifically, this study will discuss the relationship between increased blood glucose levels after STZ injection and the process of beta-amyloid formation and insulin dysfunction in the brain.

Matched MeSH terms: Amyloid beta-Peptides/metabolism
Pediococcus pentosaceus LAB6- and Lactiplantibacillus plantarum LAB12-Derived Cell Free Supernatant Inhibited RhoA Activation and Reduced Amyloid-Β In Vitro

Zaki RM, Ramasamy K, Ahmad Alwi NA, Mohd Yusoff R, Lim SM

Probiotics Antimicrob Proteins, 2024 Feb;16(1):62-75.
PMID: 36443559 DOI: 10.1007/s12602-022-10009-7

Alzheimer's disease (AD) is characterized by aggregation of amyloid beta (Aβ) plaque. RhoA may serve as a potential target for prevention against AD given its role in the amyloidogenic pathway. The recent emergence of the gut-brain axis has linked lactic acid bacteria (LAB) to neuroprotection against AD. This study assessed the importance of RhoA inhibition in mediating the neuroprotective potential of LAB. To this end, de Man, Rogosa and Sharpe (MRS) broth fermented by lactobacilli or pediococci were tested against SK-N-SH (a human neuroblastoma cell line) in the presence of RhoA activator II for 24 h after which the RhoA activity was measured using the G-LISA Kit. Fluorescence staining of f-actin stress fibres was performed to validate RhoA inhibition. SK-N-SH was transfected with plasmid expressing amyloid precursor protein (APP) gene. The Aβ concentration in transfected cells exposed to LAB-derived cell free supernatant (CFS) in the presence of RhoA activator II was measured using the ELISA kit. Furthermore, this study measured organic acids in LAB-derived CFS using the gas chromatography. It was found that LAB-derived CFS yielded strain-dependent inhibition of RhoA, with LAB6- and LAB12-derived CFS being the most potent Pediococcal- and Lactiplantibacillus-based RhoA inhibitor, respectively. Lesser stress fibres were formed under treatment with LAB-derived CFS. The LAB-derived CFS also significantly inhibited Aβ in SK-N-SH transfected with APP gene in the presence of RhoA activator II. The LAB-derived CFS was presented with increased lactic acid, acetic acid, butyric acid and propionic acid. The present findings warrant in-depth study using animal models.

Matched MeSH terms: Amyloid beta-Peptides/metabolism
Behavioural Effects and RNA-seq Analysis of Aβ42-Mediated Toxicity in a Drosophila Alzheimer's Disease Model

Tan FHP, Azzam G, Najimudin N, Shamsuddin S, Zainuddin A

Mol Neurobiol, 2023 Aug;60(8):4716-4730.
PMID: 37145377 DOI: 10.1007/s12035-023-03368-x

Alzheimer's disease (AD) is the most common neurological ailment worldwide. Its process comprises the unique aggregation of extracellular senile plaques composed of amyloid-beta (Aβ) in the brain. Aβ42 is the most neurotoxic and aggressive of the Aβ42 isomers released in the brain. Despite much research on AD, the complete pathophysiology of this disease remains unknown. Technical and ethical constraints place limits on experiments utilizing human subjects. Thus, animal models were used to replicate human diseases. The Drosophila melanogaster is an excellent model for studying both physiological and behavioural aspects of human neurodegenerative illnesses. Here, the negative effects of Aβ42-expression on a Drosophila AD model were investigated through three behavioural assays followed by RNA-seq. The RNA-seq data was verified using qPCR. AD Drosophila expressing human Aβ42 exhibited degenerated eye structures, shortened lifespan, and declined mobility function compared to the wild-type Control. RNA-seq revealed 1496 genes that were differentially expressed from the Aβ42-expressing samples against the control. Among the pathways that were identified from the differentially expressed genes include carbon metabolism, oxidative phosphorylation, antimicrobial peptides, and longevity-regulating pathways. While AD is a complicated neurological condition whose aetiology is influenced by a number of factors, it is hoped that the current data will be sufficient to give a general picture of how Aβ42 influences the disease pathology. The discovery of molecular connections from the current Drosophila AD model offers fresh perspectives on the usage of this Drosophila which could aid in the discovery of new anti-AD medications.

Matched MeSH terms: Amyloid beta-Peptides/metabolism
Functionalized Nanoparticles: A Promising Approach for Effective Management of Alzheimer's Disease

Bogadi S, Bhaskaran M, Ravichandran V, Nesamony J, Chelliah S, Kuppusamy G, et al.

Mol Neurobiol, 2025 Aug;62(8):10915-10934.
PMID: 40234291 DOI: 10.1007/s12035-025-04917-2

The severe neurodegenerative disease known as Alzheimer's disease (AD) is typified by a progressive loss of memory and cognitive function. The prevalence of AD is rising due to an aging global population, calling for novel treatment strategies. A potential treatment option for AD that shows promise is the use of functionalized nanoparticles (NPs). Recent developments in the synthesis, design, and use of functionalized NPs in AD therapy are examined in this review. An outline of the pathophysiological mechanisms underlying AD is given in the first section, focusing on the roles played by tau protein aggregates and amyloid-beta plaques in the development of the illness. We then explore the many approaches used to functionalize NPs, such as surface alterations and bioconjugation methods, which enable accurate drug administration, targeted delivery, and enhanced biocompatibility. The review also emphasizes the therapeutic potential of functionalized NPs, highlighting their capacity to improve neuroprotection, lower amyloid-beta aggregation, and improve blood-brain barrier penetration. The potential of NPs as a tool for disease modification and symptom relief is highlighted by recent pre-clinical and clinical research. Concerns about toxicity and safety are also covered, underscoring the significance of thorough testing and the field's future directions. Functionalized NPs have great promise as a multimodal strategy to treat AD, offering patients hope for better quality of life, early diagnosis, and efficient disease treatment. This study highlights the growing role of nanotechnology in the search for novel and potent therapies for AD.

Matched MeSH terms: Amyloid beta-Peptides/metabolism
Antimicrobial peptides as an alternative to anti-tuberculosis drugs

AlMatar M, Makky EA, Yakıcı G, Var I, Kayar B, Köksal F

Pharmacol Res, 2018 02;128:288-305.
PMID: 29079429 DOI: 10.1016/j.phrs.2017.10.011

Tuberculosis (TB) presently accounts for high global mortality and morbidity rates, despite the introduction four decades ago of the affordable and efficient four-drugs (isoniazid, rifampicin, pyrazinamide and ethambutol). Thus, a strong need exists for new drugs with special structures and uncommon modes of action to effectively overcome M. tuberculosis. Within this scope, antimicrobial peptides (AMPs), which are small, cationic and amphipathic peptides that comprise a section of the innate immune system, are currently the leading potential agents for the treatment of TB. Many studies have recently illustrated the capability of anti-mycobacterial peptides to disrupt the normal mycobacterial cell wall function through various modes, thereby interacting with the intracellular targets, as well as encompassing nucleic acids, enzymes and organelles. This review presents a wide array of antimicrobial activities, alongside the associated properties of the AMPs that could be utilized as potential agents in therapeutic tactics for TB treatment.

Matched MeSH terms: Antimicrobial Cationic Peptides/pharmacology; Antimicrobial Cationic Peptides/therapeutic use*; Antimicrobial Cationic Peptides/chemistry
Novel furan-containing peptide-based inhibitors of protein arginine deiminase type IV (PAD4)

Teo CY, Tejo BA, Leow ATC, Salleh AB, Abdul Rahman MB

Chem Biol Drug Des, 2017 Dec;90(6):1134-1146.
PMID: 28581157 DOI: 10.1111/cbdd.13033

Protein arginine deiminase type IV (PAD4) is responsible for the posttranslational conversion of peptidylarginine to peptidylcitrulline. Citrullinated protein is the autoantigen in rheumatoid arthritis, and therefore, PAD4 is currently a promising therapeutic target for the disease. Recently, we reported the importance of the furan ring in the structure of PAD4 inhibitors. In this study, the furan ring was incorporated into peptides to act as the "warhead" of the inhibitors for PAD4. IC50 studies showed that the furan-containing peptide-based inhibitors were able to inhibit PAD4 to a better extent than the furan-containing small molecules that were previously reported. The best peptide-based inhibitor inhibited PAD4 reversibly and competitively with an IC50 value of 243.2 ± 2.4 μm. NMR spectroscopy and NMR-restrained molecular dynamic simulations revealed that the peptide-based inhibitor had a random structure. Molecular docking studies showed that the peptide-based inhibitor entered the binding site and interacted with the essential amino acids involved in the catalytic activity. The peptide-based inhibitor could be further developed into a therapeutic drug for rheumatoid arthritis.

Matched MeSH terms: Peptides/chemical synthesis; Peptides/metabolism; Peptides/chemistry*
Extraction and identification of α-amylase inhibitor peptides from Nephelium lappacheum and Nephelium mutabile seed protein using gastro-digestive enzymes

Evaristus NA, Wan Abdullah WN, Gan CY

Peptides, 2018 04;102:61-67.
PMID: 29510154 DOI: 10.1016/j.peptides.2018.03.001

The potential of N. lappacheum and N. mutabile seed as a source of α-amylase inhibitor peptides was explored based on the local traditional practice of using the seed. Different gastro-digestive enzymes (i.e. pepsin or chymotrypsin) or a sequential digestion were used to extract the peptides. The effects of digestion time and enzyme to substrate (E:S) ratio on the α-amylase inhibitory activity were investigated. Results showed that chymotrypsin was effective in producing the inhibitor peptides from rambutan seed protein at E:S ratio 1:20 for 1 h, whereas pepsin was more effective for pulasan seed protein under the same condition. A total of 20 and 31 novel inhibitor peptides were identified, respectively. These peptides could bind with the subsites of α-amylase (i.e. Trp58, Trp59, Tyr62, Asp96, Arg195, Asp197, Glu233, His299, Asp300, and His305) and formed a sliding barrier that preventing the formation of enzyme/substrate intermediate leading to lower α-amylase activity.

Matched MeSH terms: Peptides/isolation & purification; Peptides/pharmacology; Peptides/chemistry*
Improvement of colloidal stability in colloidal processing for highly translucent, nanosized zirconia

Chuin HC, Che Husna Azhari, Mohamed Aboras, Masfueh Razali, Andanastuti Muchtar

Sains Malaysiana, 2018;47:1591-1597.

This study aimed to improve the colloidal stability of yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP)
suspension through colloidal processing to obtain highly translucent Y-TZP. Agglomeration is often the main complication
in the processing of nanosized Y-TZP as it deteriorates mechanical and optical properties. Thus, colloidal processing
is necessary to mitigate the agglomeration in Y-TZP. The colloidal stability of Y-TZP suspension plays a key role for the
success of colloidal processing. In this study, colloidal processing was conducted at several stages, namely, dispersant
addition, pH adjustment and sedimentation. Changes in particle size and zeta potential at various stages were recorded.
The suspensions were then slip-casted to form green bodies. Green bodies were sintered and characterized for density
and translucency. The results showed that dispersant addition followed by pH adjustment effectively dispersed soft
agglomerates by introducing electrosteric stabilization, whereas sedimentation successfully segregated hard agglomerates
and contributed excellent colloidal stability. With high colloidal stability, the translucency of Y-TZP was improved by
approximately 30%. This study demonstrated different colloidal processing stages and proved that high colloidal stability
and fine particle size are vital to produce highly translucent Y-TZP.

Matched MeSH terms: Intracellular Signaling Peptides and Proteins
Structure-informed detection and quantification of peptides in food and biological fluids

Agyei D, Pan S, Acquah C, Bekhit AEA, Danquah MK

J Food Biochem, 2019 01;43(1):e12482.
PMID: 31353495 DOI: 10.1111/jfbc.12482

Peptides with biological properties, that is, bioactive peptides, are a class of biomolecules whose health-promoting properties are increasingly being exploited in food and health products. However, research on targeted techniques for the detection and quantification of these peptides is still in its infancy. Such information is needed in order to enhance the biological and chemometric characterization of peptides and their subsequent application in the functional food and pharmaceutical industries. In this review, the role of classic techniques such as electrophoretic, chromatographic, and peptide mass spectrometry in the structure-informed detection and quantitation of bioactive peptides are discussed. Prospects for the use of aptamers in the characterization of bioactive peptides are also discussed. PRACTICAL APPLICATIONS: Although bioactive peptides have huge potential applications in the functional foods and health area, there are limited techniques in enhancing throughput detection, quantification, and characterization of these peptides. This review discusses state-of-the-art techniques relevant in complementing bioactive detection and profiling irrespective of the small number of amino acid units. Insights into challenges, possible remedies and prevailing areas requiring thorough research in the extant literature for food chemists and biotechnologists are also presented.

Matched MeSH terms: Peptides/analysis*; Peptides/pharmacology; Peptides/chemistry
Fulltext Inflammation Drives Alzheimer's Disease: Emphasis on 5-lipoxygenase Pathways

Siddiqui A, Akhtar S, Shah Z, Othman I, Kumari Y

Curr Neuropharmacol, 2021;19(6):885-895.
PMID: 32972344 DOI: 10.2174/1570159X18666200924122732

It is a known fact that inflammation affects several physiological processes, including the functioning of the central nervous system. Additionally, impairment of lipid mechanisms/pathways have been associated with a number of neurodegenerative disorders and Alzheimer's Disease (AD) is one of them. However, much attention has been given to the link between tau and beta- amyloid hypothesis in AD pathogenesis/prognosis. Increasing evidences suggest that biologically active lipid molecules could influence the pathophysiology of AD via a different mechanism of inflammation. This review intends to highlight the role of inflammatory responses in the context of AD with the emphasis on biochemical pathways of lipid metabolism enzyme, 5-lipoxygenase (5- LO).

Matched MeSH terms: Amyloid beta-Peptides
The assessment of three dimensional modelling design for single strand DNA aptamers for computational chemistry application

Sabri MZ, Hamid AAA, Hitam SMS, Rahim MZA

Biophys Chem, 2020 12;267:106492.
PMID: 33035750 DOI: 10.1016/j.bpc.2020.106492

Aptamers are oligonucleotides and peptides around 15-100 bases in length and are suitable as detection probes or as therapeutics molecules. There are growing interests in the aptamer screening approach through computational simulation methods. DNA and RNA modelling lacks of validation on their predicted 3D structures due to less number of validation tools, unlike protein structures. We suggest an approach to design the stem-loop/hairpin for the three dimensional structure of DNA aptamers through serial applications of computational prediction methods by comparing the simulated structures with the experimental data deposited in PDB Data bank, followed by MD simulations. The result shows minimal structural differences were observed between the designed and the original NMR aptamers, and the stem-loop conformational structures were also retained during the MD thus suggesting the proposed aptamers designing methods are able to synthesize a high quality molecular structure of hairpin aptamers, comparable to the NMR structures.

Matched MeSH terms: Peptides
ASP2397: a novel antifungal agent produced by Acremonium persicinum MF-347833

Nakamura I, Yoshimura S, Masaki T, Takase S, Ohsumi K, Hashimoto M, et al.

J Antibiot (Tokyo), 2017 Jan;70(1):45-51.
PMID: 27599768 DOI: 10.1038/ja.2016.107

The novel antifungal agent ASP2397 (Vical's compound ID VL-2397) is produced by the fungal strain MF-347833 that was isolated from Malaysian leaf litter and is identified here as an Acremonium species based on its morphology, physiological properties and 28S ribosomal DNA sequence. Because of its potential importance for producing novel antifungal agents, we determined the taxonomic and biologic properties of MF-347833. We show here that ASP2397 is a cyclic hexapeptide that chelates aluminum ion and is therefore similar to ferrichrome, a hydroxamate siderophore. However, ASP2397 differs structurally from licensed antifungal agents such as amphotericin B, triazoles and echinocandins. To understand the relationship between chemical structure and biological function, we isolated certain ASP2397 derivatives from the culture broth, and we further chemically converted the metal-free form to other derivatives.

Matched MeSH terms: Peptides, Cyclic/isolation & purification; Peptides, Cyclic/pharmacology*; Peptides, Cyclic/chemistry
Identification and characterization of novel α-amylase and α-glucosidase inhibitory peptides from camel whey proteins

Baba WN, Mudgil P, Kamal H, Kilari BP, Gan CY, Maqsood S

J Dairy Sci, 2021 Feb;104(2):1364-1377.
PMID: 33309363 DOI: 10.3168/jds.2020-19271

This study explores the inhibitory properties of camel whey protein hydrolysates (CWPH) toward α-amylase (AAM) and α-glucosidase (AG). A general full factorial design (3 × 3) was applied to study the effect of temperature (30, 37, and 45°C), time (120, 240, and 360 min), and enzyme (pepsin) concentration (E%; 0.5, 1, and 2%). The results showed that maximum degree of hydrolysis was obtained when hydrolysis was carried out at higher temperature (45°C; P < 0.05), compared with lower temperatures of 30 and 37°C. Electrophoretic pattern displays degradation of all protein bands upon hydrolysis by pepsin at various hydrolysis conditions applied. All the 27 CWPH generated showed significant AAM and AG inhibitory potential as indicated by their lower IC50 values (mg/mL) compared with intact whey proteins. In total 196 peptides were identified from selected hydrolysates and 15 potential peptides (PepSite score > 0.8; http://pepsite2.russelllab.org/) were explored via in silico approach. Novel peptides PAGNFLMNGLMHR, PAVACCLPPLPCHM, MLPLMLPFTMGY, and PAGNFLPPVAAAPVM were identified as potential inhibitors for both AAM and AG due to their high number of binding sites and highest binding probability toward the target enzymes. CCGM and MFE, as well as FCCLGPVPP were identified as AG and AAM inhibitory peptides, respectively. This is the first study that reports novel AG and AAM inhibitory peptides from camel whey proteins. The future direction for this research involves synthesis of these potential AG and AAM inhibitory peptides in a pure form and investigate their antidiabetic properties in the in vitro, as well as in vivo models. Thus, CWPH can be considered for potential applications in glycaemic regulation.

Matched MeSH terms: Peptides/metabolism; Peptides/pharmacology*; Peptides/chemistry
Fulltext Identification polypeptide biomarkers of porcine skin gelatin by two-dimensional electrophoresis

Aina, M.A., Amin, I., Raja Mohd Hafidz, R.N., Yaakob, C.M.

International Food Research Journal, 2013;20(3):1395-1399.
MyJurnal

The peptide composition of gelatin is known to vary very common that the electrophoretic pattern of gelatin from one source differs from another source even for the same raw material. Therefore, the present study aimed to use proteomics field to identify gelatin polypeptides biomarker for depending on the condition under which collagen is hydrolyzed. Hence, it is porcine skins. The polypeptides obtained for porcine skin gelatins can be used as reference in future to detect the origins of gelatin added in the processed food. We compared porcine skin gelatin samples obtained from three producers. Total average numbers of polypeptides of porcine skin gelatins from company A, B and C were 303 ± 2.8, 285.5 ± 3.5 and 270.5 ± 4.9 spots respectively. 10 biomarkers were identified and presented in all different companies. We also did a mixture of porcine and bovine skin gelatin to detect the presence of these 10 biomarkers. The level of adulteration that could be detected was as low as 1.0% w/w

Matched MeSH terms: Peptides
Fulltext Net charge, hydrophobicity and specific amino acids contribute to the activity of antimicrobial peptides

Jindal MH, Le CF, Mohd Yusof MY, Sekaran SD

JUMMEC, 2014;17(1):1-7.
MyJurnal

Antimicrobial peptides (AMPs) have gained increasing attention as a potential candidate in the development of novel antimicrobial agent. Designing AMPs with enhanced antimicrobial activity while reducing the cell toxicity level is desired especially against the antibiotic-resistant microbes. Various approaches towards the design of AMPs have been described and physicochemical properties of AMPs represent the primary factors determining the antimicrobial potency of AMPs. The most common parameters include net charge and hydrophobicity, which greatly influence the antimicrobial activity of AMPs. Moreover, certain amino acids would have critical importance in affecting the antimicrobial activity as well as cell cytotoxicity of AMPS. In this review, net charge, hydrophobicity, and specific amino acid residues were discussed as factors contributing to the antimicrobial activity of AMPs.

Matched MeSH terms: Peptides
Fulltext Computational studies on the process of peptide bond formation

Monajemia, H., Daud, M.N., Zain, S.M., Wan Abdullah, W.A.T.

ASM Science Journal, 2012;6(2):138-143.
MyJurnal

Finding a proper transition structure for the peptide bond formation process can lead to a better understanding of the role of the ribosome in catalyzing this reaction. A potential energy surface scan was performed on the ester bond dissociation of the P-site aminoacyl-tRNA and the peptide bond formation of P-site and A-site amino acids. The full fragment of initiator tRNAi met attached to both cognate (met) and non-cognate (ala) amino acids as the P-site substrate and the methionine as the A-site amino acid was used in this study. Due to the large size of tRNA, ONIOM calculations were used to reduce the computational cost. This study illustrated that the rate of peptide bond formation was reduced for misacylated tRNA without the presence of ribosomal bases. This demonstrated that there were indeed specific structural interactions involving the amino acid side chain within the tRNAi met.

Matched MeSH terms: Peptides

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