scholarly journals Enantiomeric Effect of d-Amino Acid Substitution on the Mechanism of Action of α-Helical Membrane-Active Peptides

2017 ◽  
Vol 19 (1) ◽  
pp. 67 ◽  
Author(s):  
Shiyu Sun ◽  
Guangxu Zhao ◽  
Yibing Huang ◽  
Mingjun Cai ◽  
Qiuyan Yan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Mechanism Of Action ◽  
Active Peptides ◽  
Membrane Active Peptides

Lachesana tarabaevi, an expert in membrane-active toxins

2016 ◽  
Vol 473 (16) ◽  
pp. 2495-2506 ◽  
Author(s):  
Alexey I. Kuzmenkov ◽  
Maria Y. Sachkova ◽  
Sergey I. Kovalchuk ◽  
Eugene V. Grishin ◽  
Alexander A. Vassilevski
Keyword(s):  
Amino Acid ◽  
Cleavage Sites ◽  
Amino Acid Residues ◽  
Disulfide Bridges ◽  
Venom Protein ◽  
Active Peptides ◽  
Amphiphilic Molecules ◽  
Helical Wheel ◽  
Membrane Active Peptides ◽  
Covalently Linked

In the present study, we show that venom of the ant spider Lachesana tarabaevi is unique in terms of molecular composition and toxicity. Whereas venom of most spiders studied is rich in disulfide-containing neurotoxic peptides, L. tarabaevi relies on the production of linear (no disulfide bridges) cytolytic polypeptides. We performed full-scale peptidomic examination of L. tarabaevi venom supported by cDNA library analysis. As a result, we identified several dozen components, and a majority (∼80% of total venom protein) exhibited membrane-active properties. In total, 33 membrane-interacting polypeptides (length of 18–79 amino acid residues) comprise five major groups: repetitive polypeptide elements (Rpe), latarcins (Ltc), met-lysines (MLys), cyto-insectotoxins (CIT) and latartoxins (LtTx). Rpe are short (18 residues) amphiphilic molecules that are encoded by the same genes as antimicrobial peptides Ltc 4a and 4b. Isolation of Rpe confirms the validity of the iPQM (inverted processing quadruplet motif) proposed to mark the cleavage sites in spider toxin precursors that are processed into several mature chains. MLys (51 residues) present ‘idealized’ amphiphilicity when modelled in a helical wheel projection with sharply demarcated sectors of hydrophobic, cationic and anionic residues. Four families of CIT (61–79 residues) are the primary weapon of the spider, accounting for its venom toxicity. Toxins from the CIT 1 and 2 families have a modular structure consisting of two shorter Ltc-like peptides. We demonstrate that in CIT 1a, these two parts act in synergy when they are covalently linked. This finding supports the assumption that CIT have evolved through the joining of two shorter membrane-active peptides into one larger molecule.

scholarly journals Mechanism of Action of pH-Triggered, Membrane Active Peptides: Effect of Negative Charge

2018 ◽  
Vol 114 (3) ◽  
pp. 376a
Author(s):  
Sarah Y. Kim ◽  
William C. Wimley ◽  
Kalina Hristova
Keyword(s):  
Mechanism Of Action ◽  
Negative Charge ◽  
Active Peptides ◽  
Membrane Active Peptides

scholarly journals Mechanism of Action of pH-Triggered, Membrane Active Peptides

2019 ◽  
Vol 116 (3) ◽  
pp. 83a
Author(s):  
Sarah Y. Kim ◽  
Anna Pittman ◽  
Gavin King ◽  
William C. Wimley ◽  
Kalina Hristova
Keyword(s):  
Mechanism Of Action ◽  
Active Peptides ◽  
Membrane Active Peptides

Amino acid-induced impairment of glucose oxidation by isolated rat muscle: mechanism of action

2007 ◽  
Vol 115 (S 1) ◽  
Author(s):  
K Stadlbauer ◽  
B Brunmair ◽  
Z Szöcs ◽  
M Krebs ◽  
A Luger ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mechanism Of Action ◽  
Glucose Oxidation ◽  
Rat Muscle ◽  
Isolated Rat

The minimal amino acid sequence of the insulin-potentiating fragments of human growth hormone: its mechanism of action

Diabetes ◽  
1980 ◽  
Vol 29 (10) ◽  
pp. 782-787 ◽  
Author(s):  
F. M. Ng ◽  
J. Bornstein ◽  
C. E. Pullin ◽  
J. O. Bromley ◽  
S. L. Macaulay
Keyword(s):  
Growth Hormone ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Human Growth Hormone ◽  
Mechanism Of Action ◽  
Human Growth

Hubsm: A Novel Amino Acid Substitution Matrix for Comparing Hub Proteins

2017 ◽  
Vol 7 (8) ◽  
pp. 212
Author(s):  
Renganayaki G. ◽  
Achuthsankar S. Nair
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Low Complexity ◽  
Database Search ◽  
Substitution Matrix ◽  
Compositional Bias ◽  
Sequence Alignments ◽  
Amino Acid Substitution Matrix ◽  
Alignment Algorithms ◽  
Hub Proteins

Sequence alignment algorithms and  database search methods use BLOSUM and PAM substitution matrices constructed from general proteins. These de facto matrices are not optimal to align sequences accurately, for the proteins with markedly different compositional bias in the amino acid.   In this work, a new amino acid substitution matrix is calculated for the disorder and low complexity rich region of Hub proteins, based on residue characteristics. Insights into the amino acid background frequencies and the substitution scores obtained from the Hubsm unveils the  residue substitution patterns which differs from commonly used scoring matrices .When comparing the Hub protein sequences for detecting homologs,  the use of this Hubsm matrix yields better results than PAM and BLOSUM matrices. Usage of Hubsm matrix can be optimal in database search and for the construction of more accurate sequence alignments of Hub proteins.

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