scholarly journals Identification and Target-Modification of SL-BBI: A Novel Bowman–Birk Type Trypsin Inhibitor from Sylvirana latouchii

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1254 ◽  
Author(s):  
Xi Chen ◽  
Dong Chen ◽  
Linyuan Huang ◽  
Xiaoling Chen ◽  
Mei Zhou ◽  
...  

The peptides from the ranacyclin family share similar active disulphide loop with plant-derived Bowman–Birk type inhibitors, some of which have the dual activities of trypsin inhibition and antimicrobial. Herein, a novel Bowman–Birk type trypsin inhibitor of the ranacyclin family was identified from the skin secretion of broad-folded frog (Sylvirana latouchii) by molecular cloning method and named as SL-BBI. After chemical synthesis, it was proved to be a potent inhibitor of trypsin with a Ki value of 230.5 nM and showed weak antimicrobial activity against tested microorganisms. Modified analogue K-SL maintains the original inhibitory activity with a Ki value of 77.27 nM while enhancing the antimicrobial activity. After the substitution of active P1 site to phenylalanine and P2′ site to isoleucine, F-SL regenerated its inhibitory activity on chymotrypsin with a Ki value of 309.3 nM and exhibited antiproliferative effects on PC-3, MCF-7 and a series of non-small cell lung cancer cell lines without cell membrane damage. The affinity of F-SL for the β subunits in the yeast 20S proteasome showed by molecular docking simulations enriched the understanding of the possible action mode of Bowman–Birk type inhibitors. Further mechanistic studies have shown that F-SL can activate caspase 3/7 in H157 cells and induce apoptosis, which means it has the potential to become an anticancer agent.

2020 ◽  
Author(s):  
Kaiqi Lian ◽  
Mingliang Zhang ◽  
Xiuli Liang ◽  
Lingling Zhou ◽  
Zhiqi Shi ◽  
...  

Abstract Background: The recent emergence of antibiotic-resistant strains of bacteria has increased the need to develop effective alternatives to antibiotics. Antimicrobial peptides have been considered as a promising product with several advantages.Results: In this present study, we identified a novel cecropin from the armyworm, Mythimna separata (armyworm cecropin 1, AC-1) by transcriptome sequencing and multi-sequence alignment analysis. The AC-1 precursor comprised 63 amino acid residues, containing a conserved cleavage site of the signal peptide, Ala23-Pro24, while the mature AC-1 included 39 amino acid residues. Chemically synthesized AC-1 exhibited low hemolytic activity against chicken red blood cells, low cytotoxicity against swine testis cells, and effective antimicrobial activity against Salmonella, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa. Its antimicrobial activity against Salmonella remained after incubation for 1 h at 100 °C or in 250 mM NaCl, KCl, or MgCl2 solution, implying good thermal- and salt-resistant stabilities. The bactericidal effect of AC-1 on E. coli gradually increased with increasing AC-1 concentration, resulting in deformation, severe edema, cytolysis, cell membrane damage, and reducing intracellular electron density. Additionally, recombinant AC-1 protein expressed in E. coli was digested by enterokinase protease to obtain AC-1, which showed similar antimicrobial activity against E. coli to chemically synthesized AC-1.Conclusions: This study identified a novel antimicrobial peptide that may represent a potential alternative to antibiotics.


2020 ◽  
Author(s):  
Kaiqi Lian ◽  
Mingliang Zhang ◽  
Xiuli Liang ◽  
Lingling Zhou ◽  
Zhiqi Shi ◽  
...  

Abstract Background: The recent emergence of antibiotic-resistant strains of bacteria has increased the need to develop effective alternatives to antibiotics. Antimicrobial peptides have been considered as a promising product with several advantages.Results: In this present study, we identified a novel cecropin from the armyworm, Mythimna separata (armyworm cecropin 1, AC-1) by transcriptome sequencing and multi-sequence alignment analysis. The AC-1 precursor comprised 63 amino acid residues, containing a conserved cleavage site of the signal peptide, Ala23-Pro24, while the mature AC-1 included 39 amino acid residues. Chemically synthesized AC-1 exhibited low hemolytic activity against chicken red blood cells, low cytotoxicity against swine testis cells, and effective antimicrobial activity against Salmonella, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa. Its antimicrobial activity against Salmonella remained after incubation for 1 h at 100 °C or in 250 mM NaCl, KCl, or MgCl2 solution, implying good thermal- and salt-resistant stabilities. The bactericidal effect of AC-1 on E. coli gradually increased with increasing AC-1 concentration, resulting in deformation, severe edema, cytolysis, cell membrane damage, and reducing intracellular electron density. Additionally, recombinant AC-1 protein expressed in E. coli was digested by enterokinase protease to obtain AC-1, which showed similar antimicrobial activity against E. coli to chemically synthesized AC-1.Conclusions: This study identified a novel antimicrobial peptide that may represent a potential alternative to antibiotics.


2020 ◽  
Author(s):  
Kaiqi Lian ◽  
Mingliang Zhang ◽  
Xiuli Liang ◽  
Lingling Zhou ◽  
Zhiqi Shi ◽  
...  

Abstract Background: The recent emergence of antibiotic-resistant strains of bacteria has increased the need to develop effective alternatives to antibiotics. Antimicrobial peptides have been considered as a promising product with several advantages. Results: In this present study, we identified a novel cecropin from the armyworm, Mythimna separata (armyworm cecropin 1, AC-1) by transcriptome sequencing and multi-sequence alignment analysis . The AC-1 precursor comprised 63 amino acid residues, containing a conserved cleavage site of the signal peptide, Ala 23 -Pro 24 , while the mature AC-1 included 39 amino acid residues. Chemically-synthesized AC-1 exhibited low hemolytic activity against chicken red blood cells, low cytotoxicity against swine testis cells, and effective antimicrobial activity against Salmonella , Escherichia coli ( E. c oli ), Klebsiella pneumonia ( K. pneumonia ), and Pseudomonas aeruginosa ( P . aeruginosa ). Its antimicrobial activity against Salmonella remained after incubation for 1 h at 100 °C or in 250 mM NaCl, KCl, and MgCl 2 solution, implying good thermal- and salt-resistant stabilities. The bactericidal effect of AC-1 on E. c oli gradually increased with the increase of AC-1 concentration, and AC-1 could cause significant deformation , severe edema, cytoplasmic lysis, cell membrane damage of E. c oli , and reduce intracellular electron density. Additionally, the fusion protein AC-1 expressed in E. coli was digested by enterokinase protease to obtain the AC-1, which showed similar antimicrobial activity against E. c oli with chemically-synthesized AC-1. Conclusions: This study identified a novel antimicrobial peptide that may represent a potential alternative to antibiotics.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Luce M. Mattio ◽  
Sabrina Dallavalle ◽  
Loana Musso ◽  
Rossella Filardi ◽  
Laura Franzetti ◽  
...  

AbstractPlant polyphenolic compounds are considered a promising source for new antibacterial agents. In this study, we evaluated the antimicrobial activity of a collection of resveratrol-derived monomers and dimers screened as single molecules against a panel of nine foodborne pathogens. The results demonstrated that two monomers (i.e., pterostilbene 2 and (E)-3-hydroxy-4′,5-dimethoxystilbene 9) and three dimers (i.e., δ-viniferin 10, viniferifuran 14 and dehydro-δ-viniferin 15) were endowed with significant antibacterial activity against gram-positive bacteria. The exposure of gram-positive foodborne pathogens to 100 µg/mL of 2, 9 and 15 induced severe cell membrane damage, resulting in the disruption of the phospholipid bilayer. The most promising dimeric compound, dehydro-δ-viniferin 15, was tested against Listeria monocytogenes, resulting in a loss of cultivability, viability and cell membrane potential. TEM analysis revealed grave morphological modifications on the cell membrane and leakage of intracellular content, confirming that the cell membrane was the principal biological target of the tested derivative.


2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.


1976 ◽  
Vol 155 (2) ◽  
pp. 345-351 ◽  
Author(s):  
J G. Beeley

Cleavage of the two methionine residues in the glycoprotein trypsin inhibitor ovomucoid, variant O1, with CNBr resulted in two fragments whose mol.wts. were approx. 16 600 (fragment LS) and 11 000 (fragment M). Both fragments formed precipitates with antisera to ovomucoid. Fragment LS retained 56% of the trypsin-inhibitory activity of ovomucoid, but fragment M did not inhibit. After reduction and alkylation, the molecular weight of fragment M was unchanged, but fragment LS could be resolved into two segments of peptide chain with mol.wts. of approx. 12000 (fragment L) and 4700 (fragment S). Each of these peptides contained carbohydrate. Marked heterogeneity was observed in the hexose and hexosamine contents of fragment L. This may account for much of the heterogeneity in neutral carbohydrate occurring in ovomucoid preparations. It was found that fragment M was located at the N-terminal end, fragment S was in the centre and fragment L made up the C-terminal portion of the molecule.


2017 ◽  
Vol 15 (1) ◽  
pp. 332-343 ◽  
Author(s):  
Karolina A. Wojtunik-Kulesza ◽  
Katarzyna Targowska-Duda ◽  
Katarzyna Klimek ◽  
Grażyna Ginalska ◽  
Krzysztof Jóźwiak ◽  
...  

AbstractAlzheimer’s disease (AD) is by far the most prevalent of all known forms of dementia. Despite wide-spread research, the main causes of emergence and development of AD have not been fully recognized. Natural, low-molecular, lipophilic terpenoids constitute an interesting group of secondary plant metabolites, that exert biological activities of possible use in the prevention and treatment of AD. In order to identify secondary metabolites possessing both antioxidant activity and the potential to increase the level of acetylcholine, selected terpenoids have been screened for possible acetylcholinesterase inhibitory activity by use of two methods, namely Marston (chromatographic assay) and Ellman (spectrophotometric assay). In order to describe the interaction between terpenes and AChE active gorge, molecular docking simulations were performed. Additionally, all analyzed terpenes were also evaluated for their cytotoxic properties against two normal cell lines using MTT assay. The obtained results show that: carvone (6), pulegone (8) and γ-terpinene (7) possess desirable AChE inhibitory activity. MTT assay revealed low or lack of cytotoxicity of these metabolites. Thus, among the investigated terpenes, carvone (6), pulegone (8) and y-terpinene (7) can be recognized as compounds with most promising activities in the development of multi-target directed ligands.


2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Muhammad Yasir ◽  
Basit Zeshan ◽  
Nur Hardy A. Daud ◽  
Izzah Shahid ◽  
Hafza Khalid

Abstract There is a need for more efficient and eco-friendly approaches to overcome increasing microbial infections. Bacteriocins and chitinases from Bacillus spp. can be powerful alternatives to conventional antibiotics and antifungal drugs, respectively. The purpose of this study was to assess the inhibitory potential of bacteriocins and chitinase enzymes against multiple resistant bacterial and fungal pathogens. Bacterial isolates were selected by growth on minimal salts medium and after that were morphologically and biochemically characterized. The physiochemical characterization of bacteriocins was carried out. The inhibitory potential of bacteriocins towards six pathogenic bacteria was determined by the well diffusion assay while chitinase activity towards three fungal strains was determined by the dual plate culture assay. Two bacterial strains (WW2P1 and WRE4P2), out of nine showed inhibition of K. pneumonia, P. aeruginosa, E. coli and MRSA while WW4P2 was positive against S. typhimurium and E. coli and WRE10P2 against P. aeruginosa, S. pneumoniae. Two bacterial isolates (WW3P1 and WRE10P2) were chosen for further study on the basis of their antifungal activities. Of these, WW3P1 isolate was more effective against A. fumigatus as well as A. niger. The proteinaceous nature of the bacteriocins was confirmed by treatment of the crude extract with proteinase K. It was found that the inhibitory activity of strain WW3P1 against E. coli was highest at 20 °C, and against S. pneumoniae it was at 20 °C and pH 10 after treatment with EDTA. Inhibition by strain the WRE10P2 against P. aeruginosa was highest at 20 °C and pH 14. It was found that EDTA increased the inhibitory activity of strain WW2P1 against P. aeruginosa, K. pneumoniae and E. coli by 2 ± 0.235, 3.5 ± 0.288, 2.5 ± 1.040 times, respectively, of strain WRE4P2 against P. aeruginosa and E. coli by 2.5 ± 0.763, 2.7 ± 0.5 times, respectively, and of strain WRE10P2 against S. pneumoniae by 3 ± 0.6236 times. The isolates have promising inhibitory activity, which should be further analyzed for the commercial production of antimicrobials. Article highlights The current study aimed to isolate the microbiome from wheat plant (Triticum aestivum L.), to screen for bacteriocin production and to assess its antimicrobial activity against human pathogens. Forty-one phenotypically different bacterial colonies were subjected to bacteriocin purification from which 25 colonies showed positive reactions. These 25 bacterial isolates were screened against six different human bacterial pathogens using the well diffusion method to check the antimicrobial activity. Out of nine bacterial isolates, WW3P1 and WRE10P2 were able to degrade the chitin and utilize it as their sole energy source. Strain WRE4P2 exhibited partial inactivation in its activity against MRSA after treatment with proteinase K.


2021 ◽  
Author(s):  
Delaram Poormoghadam ◽  
Bita Rasoulian Shiadeh ◽  
Fereshte Azedi ◽  
Hani Tavakol ◽  
Seyed Mahdi Rezayat ◽  
...  

Abstract Spinal cord injury (SCI) is a debilitating condition for which no definitive treatment has yet been identified. Noteworthy, it influences other tissues through inflammatory reactions and metabolic disturbance. Therefore, fingolimod (FTY-720) as an FDA-approved inflammatory modulator would be promising. In the present study, nanocarriers at two distinct monodisperse particle sizes of 60 (nF60) and 190 (nF190) nm were prepared.The neural stem cell (NSC) viability and LDH release were studied in the face of the nanocarriers and free FTY-720. Results indicated that nanocarriers and free FTY-720 enhanced NSC viability than the control group.However, nF190 significantly induced less cell membrane damage than nF60. Nanocarriers and free FTY-720 enhanced motor neuron recovery in SCI rats, while body weight and return to bladder reflux by nF190 was significantly higher than nF60 groups. Return to bladder reflux might be due to the role of FTY-720 in regulation of detrusor muscle tone and preservation of the integrity of vessels by acting on endothelial cells. Moreover,nF190 gained higher soleus muscle weight than the free drugs;probably decreasing pro-inflammatory cytokines in soleus diminish muscular atrophy in SCI rats.To sum thing up, larger nanacarrirs with less cell membrane damage seems to be more efficient than smaller ones to manage SCI.


2021 ◽  
Author(s):  
Romina Mitarotonda ◽  
Martín Saraceno ◽  
Marcos Todone ◽  
Exequiel Giorgi ◽  
Emilio L Malchiodi ◽  
...  

Aim: Nanoparticles (NPs) interaction with immune system is a growing topic of study. Materials & methods: Bare and amine grafted silica NPs effects on monocytes/macrophages cells were analyzed by flow cytometry, MTT test and LIVE/DEAD® viability/cytotoxicity assay. Results: Bare silica NPs inhibited proliferation and induced monocyte/macrophages activation (increasing CD40/CD80 expression besides pro-inflammatory cytokines and nitrite secretion). Furthermore, silica NPs increased cell membrane damage and reduced the number of living cells. In contrast, amine grafted silica NPs did not alter these parameters. Conclusion: Cell activation properties of bare silica NPs could be hindered after grafting with amine moieties. This strategy is useful to tune the immune system stimulation by NPs or to design NPs suitable to transport therapeutic molecules.


Sign in / Sign up

Export Citation Format

Share Document