scholarly journals Modification and de novo design of non-ribosomal peptide synthetases (NRPS) using specific assembly points within condensation domains

2018 ◽  
Author(s):  
Kenan A. J. Bozhüyük ◽  
Annabell Linck ◽  
Andreas Tietze ◽  
Frank Wesche ◽  
Sarah Nowak ◽  
...  
Keyword(s):  
Amino Acids ◽  
De Novo ◽  
Covalent Binding ◽  
Efficient Production ◽  
Diverse Range ◽  
Peptide Synthetases ◽  
Catalytically Active ◽  
Peptide Derivatives ◽  
Natural Amino Acids ◽  
Exchange Unit

AbstractMany important natural products are produced by non-ribosomal peptide synthetases (NRPSs) 1.These giant enzyme machines activate amino acids in an assembly line fashion in which a set of catalytically active domains is responsible for the section, activation, covalent binding and connection of a specific amino acid to the growing peptide chain 1,2. Since NRPS are not restricted to the incorporation of the 20 proteinogenic amino acids, their efficient manipulation would give access to a diverse range of peptides available biotechnologically. Here we describe a new fusion point inside condensation (C) domains of NRPSs that enables the efficient production of peptides, even containing non-natural amino acids, in yields higher than 280 mg/L. The technology called eXchange Unit 2.0 (XU2.0) also allows the generation of targeted peptide libraries and therefore might be suitable for the future identification of bioactive peptide derivatives for pharmaceutical and other applications.

scholarly journals Recent Applications of Retro-Inverso Peptides

2021 ◽  
Vol 22 (16) ◽  
pp. 8677
Author(s):  
Nunzianna Doti ◽  
Mario Mardirossian ◽  
Annamaria Sandomenico ◽  
Menotti Ruvo ◽  
Andrea Caporale
Keyword(s):  
Amino Acids ◽  
Neurodegenerative Diseases ◽  
De Novo ◽  
3D Structure ◽  
New Drugs ◽  
Side Chains ◽  
Pros And Cons ◽  
Endogenous Proteases ◽  
Natural Amino Acids ◽  
Poor Stability

Natural and de novo designed peptides are gaining an ever-growing interest as drugs against several diseases. Their use is however limited by the intrinsic low bioavailability and poor stability. To overcome these issues retro-inverso analogues have been investigated for decades as more stable surrogates of peptides composed of natural amino acids. Retro-inverso peptides possess reversed sequences and chirality compared to the parent molecules maintaining at the same time an identical array of side chains and in some cases similar structure. The inverted chirality renders them less prone to degradation by endogenous proteases conferring enhanced half-lives and an increased potential as new drugs. However, given their general incapability to adopt the 3D structure of the parent peptides their application should be careful evaluated and investigated case by case. Here, we review the application of retro-inverso peptides in anticancer therapies, in immunology, in neurodegenerative diseases, and as antimicrobials, analyzing pros and cons of this interesting subclass of molecules.

De Novo Design of a Bolaamphiphilic Peptide with Only Natural Amino Acids

2008 ◽  
Vol 8 (11) ◽  
pp. 1053-1059 ◽  
Author(s):  
Feng Qiu ◽  
Yongzhu Chen ◽  
Chengkang Tang ◽  
Qinghan Zhou ◽  
Chen Wang ◽  
...  
Keyword(s):  
Amino Acids ◽  
De Novo ◽  
De Novo Design ◽  
Natural Amino Acids

scholarly journals Diversification in substrate usage by glutathione synthetases from soya bean (Glycine max), wheat (Triticum aestivum) and maize (Zea mays)

2005 ◽  
Vol 391 (3) ◽  
pp. 567-574 ◽  
Author(s):  
Mark Skipsey ◽  
Benjamin G. Davis ◽  
Robert Edwards
Keyword(s):  
Amino Acids ◽  
Triticum Aestivum ◽  
Molecular Basis ◽  
Soya Bean ◽  
Acyl Acceptor ◽  
Diverse Range ◽  
Thiol Antioxidant ◽  
Substrate Usage ◽  
Substrate Tolerance ◽  
Natural Amino Acids

Unlike animals which accumulate glutathione (γ-glutamyl-L-cysteinyl-glycine) alone as their major thiol antioxidant, several crops synthesize alternative forms of glutathione by varying the carboxy residue. The molecular basis of this variation is not well understood, but the substrate specificity of the respective GSs (glutathione synthetases) has been implicated. To investigate their substrate tolerance, five GS-like cDNAs have been cloned from plants that can accumulate alternative forms of glutathione, notably soya bean [hGSH (homoglutathione or γ-glutamyl-L-cysteinyl-β-alanine)], wheat (hydroxymethylglutathione or γ-glutamyl-L-cysteinyl-serine) and maize (γ-Glu-Cys-Glu). The respective recombinant GSs were then assayed for the incorporation of differing C-termini into γ-Glu-Cys. The soya bean enzyme primarily incorporated β-alanine to form hGSH, whereas the GS enzymes from cereals preferentially catalysed the formation of glutathione. However, when assayed with other substrates, several GSs and one wheat enzyme in particular were able to synthesize a diverse range of glutathione variants by incorporating unusual C-terminal moieties including D-serine, non-natural amino acids and α-amino alcohols. Our results suggest that plant GSs are capable of producing a diverse range of glutathione homologues depending on the availability of the acyl acceptor.

scholarly journals Functional Analysis of Genes Involved in the Synthesis of Syringolin A by Pseudomonas syringae pv. syringae B301D-R

2004 ◽  
Vol 17 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Hans Amrein ◽  
Stefan Makart ◽  
José Granado ◽  
Roshani Shakya ◽  
Jana Schneider-Pokorny ◽  
...  
Keyword(s):  
Amino Acids ◽  
Pseudomonas Syringae ◽  
Host Plants ◽  
Ring Structure ◽  
Type I ◽  
Compatible Interaction ◽  
Phytopathogenic Bacterium ◽  
Peptide Synthetases ◽  
Nonhost Plant ◽  
Peptide Derivatives

Strains of the phytopathogenic bacterium Pseudomonas syringae pv. syringae secrete a family of structurally closely related peptide derivatives dubbed syringolins, of which syringolin A is the major variant. The function of syringolins in the interaction of P. syringae pv. syringae with their host plants presently is unknown. It is hypothesized that they may constitute virulence factors. However, syringolins are determinants recognized and reacted to by nonhost plant species, and syringolin A has been shown to induce hypersensitive death of cells colonized by powdery mildew in wheat and, thus, to reprogram a compatible interaction into an incompatible one. Syringolin A is an unusual derivative of a tripeptide that contains a 12-membered ring consisting of the amino acids 5-methyl-4-amino-2-hexenoic acid and 3,4-dehydrolysine, two nonproteinogenic amino acids. Here we report the cloning, sequencing, and analysis of genes involved in the biosynthesis of syringolin A. The genes encode proteins consisting of modules typical for nonribosomal peptide synthetases and type I polyketide synthetases, as well as proteins likely involved in the transcriptional regulation of syringolin A biosynthesis and in syringolin A export. The structure and arrangement of the modules lead to the formulation of a model explaining the synthesis of the tripeptide, including the formation of the two nonproteinogenic amino acids in the ring structure of syringolin A.

Common modifications of selenocysteine in selenoproteins

2019 ◽  
Vol 64 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elias S.J. Arnér
Keyword(s):  
Amino Acids ◽  
Covalent Binding ◽  
Physicochemical Characteristics ◽  
Redox Active

Abstract Selenocysteine (Sec), the sulfur-to-selenium substituted variant of cysteine (Cys), is the defining entity of selenoproteins. These are naturally expressed in many diverse organisms and constitute a unique class of proteins. As a result of the physicochemical characteristics of selenium when compared with sulfur, Sec is typically more reactive than Cys while participating in similar reactions, and there are also some qualitative differences in the reactivities between the two amino acids. This minireview discusses the types of modifications of Sec in selenoproteins that have thus far been experimentally validated. These modifications include direct covalent binding through the Se atom of Sec to other chalcogen atoms (S, O and Se) as present in redox active molecular motifs, derivatization of Sec via the direct covalent binding to non-chalcogen elements (Ni, Mb, N, Au and C), and the loss of Se from Sec resulting in formation of dehydroalanine. To understand the nature of these Sec modifications is crucial for an understanding of selenoprotein reactivities in biological, physiological and pathophysiological contexts.

Antimyotoxic Activity of Synthetic Peptides Derived from Bothrops atrox Snake Gamma Phospholipase A2 Inhibitor Selected by Virtual Screening

2019 ◽  
Vol 19 (22) ◽  
pp. 1952-1961 ◽  
Author(s):  
J.C. Sobrinho ◽  
A.F. Francisco ◽  
R. Simões-Silva ◽  
A.M. Kayano ◽  
J.J. Alfonso Ruiz Diaz ◽  
...  
Keyword(s):  
Amino Acids ◽  
Molecular Docking ◽  
Synthetic Peptides ◽  
Cell Damage ◽  
Neutralization Assay ◽  
Phospholipase Activity ◽  
Phospholipases A2 ◽  
Catalytically Active ◽  
Bothrops Atrox

Background: Several studies have aimed to identify molecules that inhibit the toxic actions of snake venom phospholipases A2 (PLA2s). Studies carried out with PLA2 inhibitors (PLIs) have been shown to be efficient in this assignment. Objective: This work aimed to analyze the interaction of peptides derived from Bothrops atrox PLIγ (atPLIγ) with a PLA2 and to evaluate the ability of these peptides to reduce phospholipase and myotoxic activities. Methods: Peptides were subjected to molecular docking with a homologous Lys49 PLA2 from B. atrox venom modeled by homology. Phospholipase activity neutralization assay was performed with BthTX-II and different ratios of the peptides. A catalytically active and an inactive PLA2 were purified from the B. atrox venom and used together in the in vitro myotoxic activity neutralization experiments with the peptides. Results: The peptides interacted with amino acids near the PLA2 hydrophobic channel and the loop that would be bound to calcium in Asp49 PLA2. They were able to reduce phospholipase activity and peptides DFCHNV and ATHEE reached the highest reduction levels, being these two peptides the best that also interacted in the in silico experiments. The peptides reduced the myotubes cell damage with a highlight for the DFCHNV peptide, which reduced by about 65%. It has been suggested that myotoxic activity reduction is related to the sites occupied in the PLA2 structure, which could corroborate the results observed in molecular docking. Conclusion: This study should contribute to the investigation of the potential of PLIs to inhibit the toxic effects of PLA2s.

Sign in / Sign up

Export Citation Format

Share Document