Modulation of anti-endotoxin property of Temporin L by minor amino acid substitution in identified phenylalanine zipper sequence

2016 ◽  
Vol 473 (21) ◽  
pp. 4045-4062 ◽  
Author(s):  
Saurabh Srivastava ◽  
Amit Kumar ◽  
Amit Kumar Tripathi ◽  
Anshika Tandon ◽  
Jimut Kanti Ghosh
Keyword(s):  
Antibacterial Activity ◽  
Amino Acid ◽  
Antimicrobial Agents ◽  
Antimicrobial Property ◽  
Antimicrobial Activities ◽  
Repeat Sequence ◽  
Amino Acid Sequences ◽  
Heptad Repeat ◽  
Plausible Mechanism ◽  
Factor Α

A 13-residue frog antimicrobial peptide Temporin L (TempL) possesses versatile antimicrobial activities and is considered a lead molecule for the development of new antimicrobial agents. To find out the amino acid sequences that influence the anti-microbial property of TempL, a phenylalanine zipper-like sequence was identified in it which was not reported earlier. Several alanine-substituted analogs and a scrambled peptide having the same composition of TempL were designed for evaluating the role of this motif. To investigate whether leucine residues instead of phenylalanine residues at ‘a’ and/or ‘d’ position(s) of the heptad repeat sequence could alter its antimicrobial property, several TempL analogs were synthesized after replacing these phenylalanine residues with leucine residues. Replacing phenylalanine residues with alanine residues in the phenylalanine zipper sequence significantly compromised the anti-endotoxin property of TempL. This is evident from the higher production of tumor necrosis factor-α and interleukin-6 in lipopolysaccharide (LPS)-stimulated rat bone-marrow-derived macrophage cells in the presence of its alanine-substituted analogs than TempL itself. However, replacement of these phenylalanine residues with leucine residues significantly augmented anti-endotoxin property of TempL. A single alanine-substituted TempL analog (F8A-TempL) showed significantly reduced cytotoxicity but retained the antibacterial activity of TempL, while the two single leucine-substituted analogs (F5L-TempL and F8L-TempL), although exhibiting lower cytotoxicity, were able to retain the antibacterial activity of the parent peptide. The results demonstrate how minor amino acid substitutions in the identified phenylalanine zipper sequence in TempL could yield analogs with better antibacterial and/or anti-endotoxin properties with their plausible mechanism of action.

scholarly journals Biological and Physico-Chemical Characteristics of Arginine-Rich Peptide Gemini Surfactants with Lysine and Cystine Spacers

2021 ◽  
Vol 22 (7) ◽  
pp. 3299
Author(s):  
Damian Neubauer ◽  
Maciej Jaśkiewicz ◽  
Marta Bauer ◽  
Agata Olejniczak-Kęder ◽  
Emilia Sikorska ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Cationic Surfactants ◽  
Antimicrobial Agents ◽  
Gemini Surfactants ◽  
Antimicrobial Activities ◽  
Critical Aggregation Concentration ◽  
Cytotoxic Activities ◽  
Candida Sp ◽  
Enhanced Selectivity

Ultrashort cationic lipopeptides (USCLs) and gemini cationic surfactants are classes of potent antimicrobials. Our recent study has shown that the branching and shortening of the fatty acids chains with the simultaneous addition of a hydrophobic N-terminal amino acid in USCLs result in compounds with enhanced selectivity. Here, this approach was introduced into arginine-rich gemini cationic surfactants. L-cystine diamide and L-lysine amide linkers were used as spacers. Antimicrobial activity against planktonic and biofilm cultures of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) strains and Candida sp. as well as hemolytic and cytotoxic activities were examined. Moreover, antimicrobial activity in the presence of human serum and the ability to form micelles were evaluated. Membrane permeabilization study, serum stability assay, and molecular dynamics were performed. Generally, critical aggregation concentration was linearly correlated with hydrophobicity. Gemini surfactants were more active than the parent USCLs, and they turned out to be selective antimicrobial agents with relatively low hemolytic and cytotoxic activities. Geminis with the L-cystine diamide spacer seem to be less cytotoxic than their L-lysine amide counterparts, but they exhibited lower antibiofilm and antimicrobial activities in serum. In some cases, geminis with branched fatty acid chains and N-terminal hydrophobic amino acid resides exhibited enhanced selectivity to pathogens over human cells.

scholarly journals SYNTHESIS AND ANTIMICROBIAL EVALUATION OF QUINAZOLINONE PEPTIDE DERIVATIVES

2017 ◽  
Vol 10 (16) ◽  
pp. 7 ◽  
Author(s):  
Bhupinder Kapoor ◽  
Arshid Nabi ◽  
Reena Gupta ◽  
Mukta Gupta
Keyword(s):  
Antibacterial Activity ◽  
Amino Acid ◽  
Antimicrobial Agents ◽  
Methyl Esters ◽  
Standard Drug ◽  
Amino Acid Peptide ◽  
Chemical Structures ◽  
1H Nuclear Magnetic Resonance ◽  
Peptide Derivatives ◽  
Derivatives Of

  Objective: The increased microbial resistance against commercially available drugs initiated the development of novel and safe antimicrobial agents in last few decades. In this view, a series of amino acid/dipeptide derivatives of quinazolin-3(4H)-one was synthesized and was evaluated for their antimicrobial potential.Method: Synthesis of amino acid/peptide derivatives were carried out by coupling 5-(2-(2-chlorophenyl)-4-oxoquinazolin-3(4H)-yl)-2-hydroxy benzoic acid with amino acid/dipeptide methyl esters in the presence of dicyclohexylcarbodiimide and N-methylmorpholine. The chemical structures of synthesized compounds were characterized by 1H nuclear magnetic resonance and infrared spectroscopy and were screened for antibacterial activity by disc diffusion method.Results: All the synthesized derivatives exhibited moderate to significant antibacterial activity against both Gram-positive and Gram-negative bacteria. The potency of compound 5d was comparable to standard drug ciprofloxacin in all the strains of bacteria used. The compound 5a was found to be more active against Streptococcus pyogenes and Staphylococcus aureus while compound 5c against Pseudomonas aeruginosa and Escherichia coli. Conclusion: Peptide derivatives of quinazolinone are promising antimicrobial agent and can be used for the synthesis of other novel compounds.

scholarly journals Complete sequences of epidermin and nukacin encoding plasmids from oral-derived Staphylococcus epidermidis and their antibacterial activity

2021 ◽  
Author(s):  
Kenta Nakazono ◽  
Mi Nguyen-Tra Le ◽  
Miki Kawada-Matsuo ◽  
Noy Kimheang ◽  
Junzo Hisatsune ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Amino Acid ◽  
Staphylococcus Epidermidis ◽  
Activity Patterns ◽  
Bacterial Flora ◽  
Complete Sequence ◽  
Oral Bacteria ◽  
Amino Acid Sequences ◽  
Commensal Bacterium ◽  
Complete Sequences

AbstractStaphylococcus epidermidis is a commensal bacterium in humans. To persist in the bacterial flora of the host, some bacteria produce antibacterial factors such as the antimicrobial peptides known as bacteriocins. In this study, we tried to isolate bacteriocin-producing S. epidermidis strains. Among 150 S. epidermidis isolates from the oral cavities of 287 volunteers, we detected two bacteriocin-producing strains, KSE56 and KSE650. Complete genome sequences of the two strains confirmed that they carried the epidermin-harbouring plasmid pEpi56 and the nukacin IVK45-like- harbouring plasmid pNuk650. The amino acid sequence of epidermin from KSE56 was identical to the previously reported sequence, but the epidermin synthesis-related genes were partially different. The prepeptide amino acid sequences of nukacin KSE650 and nukacin IVK45 showed one mismatch, but both mature peptides were entirely similar. pNuk650 was larger and had an additional seven ORFs compared to pIVK45. We then investigated the antibacterial activity of the two strains against several skin and oral bacteria and found their different activity patterns. In conclusion, we report the complete sequences of 2 plasmids coding for bacteriocins from S. epidermidis, which were partially different from those previously reported. Furthermore, this is the first report to show the complete sequence of an epidermin-carrying plasmid, pEpi56.

scholarly journals Functional and Structural Roles of the Major Facilitator Superfamily Bacterial Multidrug Efflux Pumps

2020 ◽  
Vol 8 (2) ◽  
pp. 266 ◽  
Author(s):  
Sanath Kumar ◽  
Manjusha Lekshmi ◽  
Ammini Parvathi ◽  
Manisha Ojha ◽  
Nicholas Wenzel ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antimicrobial Agents ◽  
Efflux Pumps ◽  
Multidrug Resistant ◽  
Amino Acid Sequences ◽  
Major Facilitator Superfamily ◽  
Multidrug Efflux ◽  
Ion Translocation ◽  
Multidrug Efflux Pumps ◽  
Major Facilitator

Pathogenic microorganisms that are multidrug-resistant can pose severe clinical and public health concerns. In particular, bacterial multidrug efflux transporters of the major facilitator superfamily constitute a notable group of drug resistance mechanisms primarily because multidrug-resistant pathogens can become refractory to antimicrobial agents, thus resulting in potentially untreatable bacterial infections. The major facilitator superfamily is composed of thousands of solute transporters that are related in terms of their phylogenetic relationships, primary amino acid sequences, two- and three-dimensional structures, modes of energization (passive and secondary active), and in their mechanisms of solute and ion translocation across the membrane. The major facilitator superfamily is also composed of numerous families and sub-families of homologous transporters that are conserved across all living taxa, from bacteria to humans. Members of this superfamily share several classes of highly conserved amino acid sequence motifs that play essential mechanistic roles during transport. The structural and functional importance of multidrug efflux pumps that belong to the major facilitator family and that are harbored by Gram-negative and -positive bacterial pathogens are considered here.

Synthesis and Antimicrobial Evaluation of Amino Acid Naphthoquinone Derivatives as Potential Antibacterial Agents

Chemotherapy ◽  
2021 ◽  
Author(s):  
Lluvia Itzel López-López ◽  
Ernesto Rivera-Ávalos ◽  
Cecilia Villarreal-Reyes ◽  
Fidel Martínez-Gutiérrez ◽  
Denisse de Loera
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Amino Acid ◽  
Antimicrobial Activities ◽  
Biological Evaluation ◽  
Culture Collection ◽  
Anticancer Activities ◽  
Broth Microdilution Method

Background: The synthesis and biological evaluation of 1,4-naphthoquinone derivatives are of great interest since these compounds exhibit strong antibacterial, antifungal, antimalarial, and anticancer activities. The electronic properties of naphthoquinones are usually modulated by attaching functional groups containing nitrogen, oxygen and sulfur atoms, which tune their biological potency and selectivity. Methods: A series of 13 amino acid 1,4-naphthoquinone derivatives were synthesized under assisted microwave and ultrasound conditions. The antibacterial activity compounds was tested against American type Culture Collection (ATCC): Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis, as well two multidrug resistant pathogens: Escherichia coli and Staphylococcus aureus from clinical isolated. Minimal inhibitory concentration (MIC) was determined using the broth microdilution method. Results: MIC of derivatives 4–11, 14 and 16 showed antimicrobial activity against gram-positive and gram-negative bacteria. Antimicrobial activities of the compounds 4–8 and 14 were ≤MIC 24.7 μg∙mL-1 against all the reference strain, even more the compound 6 showed the most potent activity with a MIC of 3.9 μg∙mL-1 on S. aureus. On the clinical isolated the compounds 7, 8 and 14 showed a MIC of 49.7 and 24.7 μg∙mL-1 against S. aureus y E. coli respectively. About ADME properties and Osiris analysis, the compounds 4-16 presented high gastrointestinal absorption and good characteristics for oral bioavailability and the compound 14 was the less toxic. Conclusion: amino acid 1,4-naphthoquinone derivatives showed good in vitro antibacterial activity against clinical strains, and modifications on C-3 with cloride atom enhanced the efficiency against same pathogens.

Biogenic Synthesis of Gold Nanoparticles and Their Antimicrobial Activities

2020 ◽  
pp. 216-233
Author(s):  
Snežana Radisavljević ◽  
Biljana Petrović
Keyword(s):  
Drug Delivery ◽  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Food Packaging ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bactericidal Effect ◽  
Antimicrobial Activities ◽  
Physiochemical Properties

Gold nanoparticles (AuNPs) are widely used in biomedical applications, especially diagnostic and drug delivery. The antibacterial activity of nanoparticles depends on the dimensions of the particles. AuNPs may associate with the surface of the cell membrane and cause disorder such as respiration and permeability. The method of binding of particles for bacteria depends on their surface available for interaction. Smaller particles which have the larger surface area available for interaction will show better bactericidal effect than the larger particles. Useful antibacterial agents should also be toxic to various pathogenic bacteria with the ability to coat different surfaces like biomaterials, devices, textiles, food packaging, and so on. The biological and physiochemical properties of synthesized AuNPs have impact on the use of gold nanoparticles like antimicrobial agents, especially for water purification, as well as other biomedical applications.

scholarly journals Single Amino Acid Substitutions at Specific Positions of the Heptad Repeat Sequence of Piscidin-1 Yielded Novel Analogs That Show Low Cytotoxicity andIn VitroandIn VivoAntiendotoxin Activity

2016 ◽  
Vol 60 (6) ◽  
pp. 3687-3699 ◽  
Author(s):  
Amit Kumar ◽  
Amit Kumar Tripathi ◽  
Manoj Kathuria ◽  
Sonal Shree ◽  
Jitendra Kumar Tripathi ◽  
...  
Keyword(s):  
Body Weight ◽  
Biological Activity ◽  
Amino Acid ◽  
Mammalian Cells ◽  
Functional Characterization ◽  
Repeat Sequence ◽  
Heptad Repeat ◽  
Single Amino Acid ◽  
Cytotoxic Activities ◽  
Isoleucine Residue

Piscidin-1 possesses significant antimicrobial and cytotoxic activities. To recognize the primary amino acid sequence(s) in piscidin-1 that could be important for its biological activity, a long heptad repeat sequence located in the region from amino acids 2 to 19 was identified. To comprehend the possible role of this motif, six analogs of piscidin-1 were designed by selectively replacing a single isoleucine residue at a d (5th) position or at an a (9th or 16th) position with either an alanine or a valine residue. Two more analogs, namely, I5F,F6A-piscidin-1 and V12I-piscidin-1, were designed for investigating the effect of interchanging an alanine residue at a d position with an adjacent phenylalanine residue and replacing a valine residue with an isoleucine residue at another d position of the heptad repeat of piscidin-1, respectively. Single alanine-substituted analogs exhibited significantly reduced cytotoxicity against mammalian cells compared with that of piscidin-1 but appreciably retained the antibacterial and antiendotoxin activities of piscidin-1. All the single valine-substituted piscidin-1 analogs and I5F,F6A-piscidin-1 showed cytotoxicity greater than that of the corresponding alanine-substituted analogs, antibacterial activity marginally greater than or similar to that of the corresponding alanine-substituted analogs, and also antiendotoxin activity superior to that of the corresponding alanine-substituted analogs. Interestingly, among these peptides, V12I-piscidin-1 showed the highest cytotoxicity and antibacterial and antiendotoxin activities. Lipopolysaccharide (12 mg/kg of body weight)-treated mice, further treated with I16A-piscidin-1, the piscidin-1 analog with the highest therapeutic index, at a single dose of 1 or 2 mg/kg of body weight, showed 80 and 100% survival, respectively. Structural and functional characterization of these peptides revealed the basis of their biological activity and demonstrated that nontoxic piscidin-1 analogs with significant antimicrobial and antiendotoxin activities can be designed by incorporating single alanine substitutions in the piscidin-1 heptad repeat.

scholarly journals Probing Protein Folding with Sequence-Reversed α-Helical Bundles

2021 ◽  
Vol 22 (4) ◽  
pp. 1955
Author(s):  
Aikaterini Kefala ◽  
Maria Amprazi ◽  
Efstratios Mylonas ◽  
Dina Kotsifaki ◽  
Mary Providaki ◽  
...  
Keyword(s):  
Protein Folding ◽  
Amino Acid ◽  
Amino Acid Sequences ◽  
Size Exclusion ◽  
Heptad Repeat ◽  
Amino Acid Residues ◽  
Helical Bundles ◽  
X Ray Scattering ◽  
Exclusion Chromatography ◽  
Heptad Repeats

Recurrent protein folding motifs include various types of helical bundles formed by α-helices that supercoil around each other. While specific patterns of amino acid residues (heptad repeats) characterize the highly versatile folding motif of four-α-helical bundles, the significance of the polypeptide chain directionality is not sufficiently understood, although it determines sequence patterns, helical dipoles, and other parameters for the folding and oligomerization processes of bundles. To investigate directionality aspects in sequence-structure relationships, we reversed the amino acid sequences of two well-characterized, highly regular four-α-helical bundle proteins and studied the folding, oligomerization, and structural properties of the retro-proteins, using Circular Dichroism Spectroscopy (CD), Size Exclusion Chromatography combined with Multi-Angle Laser Light Scattering (SEC-MALS), and Small Angle X-ray Scattering (SAXS). The comparison of the parent proteins with their retro-counterparts reveals that while the α-helical character of the parents is affected to varying degrees by sequence reversal, the folding states, oligomerization propensities, structural stabilities, and shapes of the new molecules strongly depend on the characteristics of the heptad repeat patterns. The highest similarities between parent and retro-proteins are associated with the presence of uninterrupted heptad patterns in helical bundles sequences.

scholarly journals Comparative Structures and Evolution of Vertebrate Carboxyl Ester Lipase (CEL) Genes and Proteins with a Major Role in Reverse Cholesterol Transport

Cholesterol ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Roger S. Holmes ◽  
Laura A. Cox
Keyword(s):  
Amino Acid ◽  
Phylogenetic Analyses ◽  
Hydrolytic Enzyme ◽  
Gene Families ◽  
Repeat Sequence ◽  
Amino Acid Sequences ◽  
Sequence Alignments ◽  
Tertiary Structures ◽  
Lactating Mammary Gland ◽  
Using Data

Bile-salt activated carboxylic ester lipase (CEL) is a major triglyceride, cholesterol ester and vitamin ester hydrolytic enzyme contained within pancreatic and lactating mammary gland secretions. Bioinformatic methods were used to predict the amino acid sequences, secondary and tertiary structures and gene locations for CEL genes, and encoded proteins using data from several vertebrate genome projects. A proline-rich and O-glycosylated 11-amino acid C-terminal repeat sequence (VNTR) previously reported for human and other higher primate CEL proteins was also observed for other eutherian mammalian CEL sequences examined. In contrast, opossum CEL contained a single C-terminal copy of this sequence whereas CEL proteins from platypus, chicken, lizard, frog and several fish species lacked the VNTR sequence. Vertebrate CEL genes contained 11 coding exons. Evidence is presented for tandem duplicated CEL genes for the zebrafish genome. Vertebrate CEL protein subunits shared 53–97% sequence identities; demonstrated sequence alignments and identities for key CEL amino acid residues; and conservation of predicted secondary and tertiary structures with those previously reported for human CEL. Phylogenetic analyses demonstrated the relationships and potential evolutionary origins of the vertebrate CEL family of genes which were related to a nematode carboxylesterase (CES) gene and five mammalian CES gene families.

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