1.Partial purification and characterization of antimicrobial peptide(s) from Mimosa pudica (Mimosaceae)
Johnalyn C. Go ; Marilou G. Nicolas ; Gracia Fe B. Yu
Philippine Journal of Health Research and Development 2021;25(4):14-22
Plants have been a major source of natural products for sustaining human health. The use of the different parts of the plant as infusions, decoctions, extracts, and powders are being employed in the treatment of different diseases in humans, plants, and animals. One property of great significance in terms of therapeutic treatments, especially with the emergence of multi-drug resistant microbes, is the antimicrobial activity. A new promising source of antimicrobials that demonstrate novel mechanisms of therapeutic strategies is low molecular weight peptides. In this study, the antimicrobial activities of Mimosa pudica crude and partially purified peptide extracts against Gram-negative Enterobacter cloacae ATCC 23355 and Enterobacter aerogenes ATCC 13048, and Gram-positive Staphylococcus epidermidis ATCC 12228 using resazurin colorimetric assay and tricine SDS-PAGE bioautography were reported. M. pudica crude and partially purified extracts exhibited antimicrobial activity against all the bacteria tested. Specifically, the peptide that was partially purified from M. pudica with a molecular weight of 5.14 kDa inhibited the growth of Enterobacter cloacae.
Antimicrobial Peptides
2.An antibacterial peptides recognition method based on BERT and Text-CNN.
Xiaofang XU ; Chunde YANG ; Kunxian SHU ; Xinpu YUAN ; Mocheng LI ; Yunping ZHU ; Tao CHEN
Chinese Journal of Biotechnology 2023;39(4):1815-1824
Antimicrobial peptides (AMPs) are small molecule peptides that are widely found in living organisms with broad-spectrum antibacterial activity and immunomodulatory effect. Due to slower emergence of resistance, excellent clinical potential and wide range of application, AMP is a strong alternative to conventional antibiotics. AMP recognition is a significant direction in the field of AMP research. The high cost, low efficiency and long period shortcomings of the wet experiment methods prevent it from meeting the need for the large-scale AMP recognition. Therefore, computer-aided identification methods are important supplements to AMP recognition approaches, and one of the key issues is how to improve the accuracy. Protein sequences could be approximated as a language composed of amino acids. Consequently, rich features may be extracted using natural language processing (NLP) techniques. In this paper, we combine the pre-trained model BERT and the fine-tuned structure Text-CNN in the field of NLP to model protein languages, develop an open-source available antimicrobial peptide recognition tool and conduct a comparison with other five published tools. The experimental results show that the optimization of the two-phase training approach brings an overall improvement in accuracy, sensitivity, specificity, and Matthew correlation coefficient, offering a novel approach for further research on AMP recognition.
Anti-Bacterial Agents/chemistry*
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Amino Acid Sequence
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Antimicrobial Cationic Peptides/chemistry*
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Antimicrobial Peptides
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Natural Language Processing
3.Progress on the design and optimization of antimicrobial peptides.
Ruonan ZHANG ; Di WU ; Yitian GAO
Journal of Biomedical Engineering 2022;39(6):1247-1253
Antimicrobial peptides (AMPs) are a class of peptides widely existing in nature with broad-spectrum antimicrobial activity. It is considered as a new alternative to traditional antibiotics because of its unique mechanism of antimicrobial activity. The development and application of natural AMPs are limited due to their drawbacks such as low antimicrobial activity and unstable metabolism. Therefore, the design and optimization of derived peptides based on natural antimicrobial peptides have become recent research hotspots. In this paper, we focus on ribosomal AMPs and summarize the design and optimization strategies of some related derived peptides, which include reasonable primary structure modification, cyclization strategy and computer-aided strategy. We expect to provide ideas for the design and optimization of antimicrobial peptides and the development of anti-infective drugs through analysis and summary in this paper.
Antimicrobial Cationic Peptides/chemistry*
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Antimicrobial Peptides
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Drug Design
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Anti-Infective Agents/pharmacology*
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Anti-Bacterial Agents
4.Observation on time-effect for the stimulating at Zusanli (ST 36) with minimally invasive embedding with PGLA in the healthy person.
Xin LIANG ; Hong-Fang NIE ; Xun-Rui HOU ; Yu-Wei LU ; Li-Hong LI ; Meng-Dan ZHOU ; Rui-Xian ZHOU ; Tong-Tao FAN
Chinese Acupuncture & Moxibustion 2019;39(4):391-395
OBJECTIVE:
To explore the objectivity and time-effect of stimulating effect at acupoint with PGLA in the healthy person, and to provide a basis for the rational interval of minimally invasive embedding of PGLA.
METHODS:
Before embedding, 8 h, 3rd, 7th, 10th, 14th day after embedding, medical imaging magnetic resonance imaging (MRI) scanning technique was used to collect local T2WI pressure-lowering and T2-Mapping 8 echoes sequence image of left Zusanli (ST 36) in 8 cases of healthy person. The T2-Mapping 8 echoes sequence image was generated by the relevant software to the T2-Mapping image and the local T2 value was measured. The characteristics of local T2WI pressure-fat image signal intensity and the change of T2 value at left Zusanli (ST 36) with minimally invasive embedding with PGLA were observed and analyzed.
RESULTS:
①There was no abnormal signal on the T2WI pressure-fat image on the left Zusanli (ST 36) point before the embedding. The high-signal was seen on the local T2WI pressure-fat image at each time point after embedding, there was no significant difference in local signal intensity between 8 h, 3rd and 7th day after embedding. The local signal intensity decreased on the 10th day after embedding, and the local signal intensity decreased significantly on the 14th day after embedding.②The T2 value at each time point after embedding increased significantly compared with that before embedding (all <0.01); there was no significant difference in T2 value among the 8 h, 3rd and 7th day after embedding (all >0.05); there was no significant difference between the T2 value on the 7th and the 10th day after embedding (>0.05),the T2 value on the 14th day after embedding was significantly lower than that on the 7th day after embedding (<0.01).
CONCLUSION
It has a stimulating effect on the local acupoints with minimally invasive embedding with PGLA in the healthy person, and the stimulating effect has certain time-effect. The effective stimulation time is about 2 weeks. The rational interval period for the minimally invasive embedding with the PGLA of the same specification type should be about 2 weeks.
Acupuncture Points
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Antimicrobial Cationic Peptides
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Magnetic Resonance Imaging
5.Identification of the target site of antimicrobial peptide AMP-17 against Candida albicans.
Longbing YANG ; Zhuqing TIAN ; Luoxiong ZHOU ; Chaoqin SUN ; Mingjiao HUANG ; Chunren TIAN ; Jian PENG ; Guo GUO
Chinese Journal of Biotechnology 2023;39(1):304-317
Candida albicans is one of the major causes of invasive fungal infections and a serious opportunistic pathogen in immunocompromised individuals. The antimicrobial peptide AMP-17 has prominent anti-Candida activity, and proteomic analysis revealed significant differences in the expression of cell wall (XOG1) and oxidative stress (SRR1) genes upon the action of AMP-17 on C. albicans, suggesting that AMP-17 may exert anti-C. albicans effects by affecting the expression of XOG1 and SRR1 genes. To further investigate whether XOG1 and SRR1 genes were the targets of AMP-17, C. albicans xog1Δ/Δ and srr1Δ/Δ mutants were constructed using the clustered regulatory interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9) system. Phenotypic observations revealed that deletion of two genes had no significant effect on C. albicans growth and biofilm formation, whereas XOG1 gene deletion affected in vitro stress response and mycelium formation of C. albicans. Drug sensitivity assay showed that the MIC80 values of AMP-17 against xog1Δ/Δ and srr1Δ/Δ mutants increased from 8 μg/mL (for the wild type C. albicans SC5314) to 16 μg/mL, while the MIC80 values against srr1Δ/Δ: : srr1 revertants decreased to the level of the wild type SC5314. In addition, the ability of AMP-17 to inhibit biofilm formation of both deletion strains was significantly reduced compared to that of wild type SC5314, indicating that the susceptibility of the deletion mutants to AMP-17 was reduced in both the yeast state and during biofilm formation. These results suggest that XOG1 and SRR1 genes are likely two of the potential targets for AMP-17 to exert anti-C. albicans effects, which may facilitate further exploration of the antibacterial mechanism of novel peptide antifungal drugs.
Humans
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Candida albicans
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Antimicrobial Peptides
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Proteomics
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Peptides/pharmacology*
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Transcription Factors/metabolism*
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Antifungal Agents/pharmacology*
6.Role of hepcidin in the pathophysiology and diagnosis of anemia.
Blood Research 2013;48(1):10-15
This review summarizes the central role of hepcidin in the iron homeostasis mechanism, the molecular mechanism that can alter hepcidin expression, the relationship between hepcidin and erythropoiesis, and the pathogenetic role of hepcidin in different types of anemia. In addition, the usefulness of hepcidin dosage is highlighted, including the problems associated with analytical methods currently used as well as the measures of its molecular isoforms. Considering the central role of hepcidin in iron arrangement, it is reasonable to ponder its therapeutic use mainly in cases of iron overload. Further clinical trials are required before implementation.
Anemia
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Antimicrobial Cationic Peptides
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Cation Transport Proteins
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Erythropoiesis
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Homeostasis
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Iron
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Iron Overload
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Protein Isoforms
7.Role of hepcidin in the pathophysiology and diagnosis of anemia.
Blood Research 2013;48(1):10-15
This review summarizes the central role of hepcidin in the iron homeostasis mechanism, the molecular mechanism that can alter hepcidin expression, the relationship between hepcidin and erythropoiesis, and the pathogenetic role of hepcidin in different types of anemia. In addition, the usefulness of hepcidin dosage is highlighted, including the problems associated with analytical methods currently used as well as the measures of its molecular isoforms. Considering the central role of hepcidin in iron arrangement, it is reasonable to ponder its therapeutic use mainly in cases of iron overload. Further clinical trials are required before implementation.
Anemia
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Antimicrobial Cationic Peptides
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Cation Transport Proteins
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Erythropoiesis
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Homeostasis
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Iron
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Iron Overload
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Protein Isoforms
8.Understanding and exploiting hepcidin as an indicator of anemia due to chronic kidney disease.
Derek S LARSON ; Daniel W COYNE
Kidney Research and Clinical Practice 2013;32(1):11-15
Hepcidin, produced by the liver, is the master regulator of iron balance. Serum hepcidin is increased by high iron stores, blocks intestinal iron absorption, and impairs storage iron release. Conversely, iron deficiency lowers hepcidin levels and enhances intestinal iron absorption and the release of storage iron. As with ferritin, hepcidin is an acute phase reactant. Consequently, inflammation increases hepcidin and leads to impaired iron absorption, lowers serum iron and transferrin saturation, and contributes to the anemia of chronic kidney disease (CKD). We review the physiology of iron absorption, its relationship to hepcidin and the transmembrane iron transporter ferroportin, the role of hepcidin in CKD related anemia, and the possible diagnostic implications and limitations of using hepcidin as a marker of iron status.
Absorption
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Anemia
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Antimicrobial Cationic Peptides
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Cation Transport Proteins
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Ferritins
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Inflammation
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Iron
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Liver
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Renal Insufficiency, Chronic
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Transferrin
9.Understanding and exploiting hepcidin as an indicator of anemia due to chronic kidney disease.
Derek S LARSON ; Daniel W COYNE
Kidney Research and Clinical Practice 2013;32(1):11-15
Hepcidin, produced by the liver, is the master regulator of iron balance. Serum hepcidin is increased by high iron stores, blocks intestinal iron absorption, and impairs storage iron release. Conversely, iron deficiency lowers hepcidin levels and enhances intestinal iron absorption and the release of storage iron. As with ferritin, hepcidin is an acute phase reactant. Consequently, inflammation increases hepcidin and leads to impaired iron absorption, lowers serum iron and transferrin saturation, and contributes to the anemia of chronic kidney disease (CKD). We review the physiology of iron absorption, its relationship to hepcidin and the transmembrane iron transporter ferroportin, the role of hepcidin in CKD related anemia, and the possible diagnostic implications and limitations of using hepcidin as a marker of iron status.
Absorption
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Anemia
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Antimicrobial Cationic Peptides
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Cation Transport Proteins
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Ferritins
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Inflammation
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Iron
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Liver
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Renal Insufficiency, Chronic
;
Transferrin
10.Research advances of hepcidin expression and its regulation mechanism.
Chun-Kang CHANG ; Xi ZHANG ; Chao XIAO ; Shu-Cheng GU ; Xiao LI
Journal of Experimental Hematology 2012;20(4):1030-1033
Hepcidin can regulate cell irons' efflux transport. The expression of hepcidin can be influenced by the body signals (such as serum ferritin and erythropoietin levels) as well as inflammation, hypoxia and other disease states. These stimulus activate the signaling pathway of BMP-the SMAD, the JAK-STAT and HIF1 through the liver parenchymal cell surface type I transmembrane glycoprotein of HFE, transferrin receptor 1, 2, hepcidin regulatory proteins, thereby changing the hepcidin gene transcription, regulating the expression levels of hepcidin. However, the molecular mechanism that regulate hepcidin expression is unclear. From the signal factors that affect hepcidin expression and signaling pathways involved in its expression, the latest research progress on regulatory mechanism of hepcidin are summarized.
Animals
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Antimicrobial Cationic Peptides
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metabolism
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Hepcidins
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Humans
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Membrane Proteins
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metabolism
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Signal Transduction