Isolation, amino acid sequence and synthesis of dermaseptin, a novel antimicrobial peptide of amphibian skin

Biochemistry ◽  
1991 ◽  
Vol 30 (36) ◽  
pp. 8824-8830 ◽  
Author(s):  
Amram Mor ◽  
Nguyen Van Huong ◽  
Antoine Delfour ◽  
Daniele Migliore-Samour ◽  
Pierre Nicolas
1997 ◽  
Vol 24 (5) ◽  
pp. 571 ◽  
Author(s):  
Stuart J. Harrison ◽  
John P. Marcus ◽  
Kenneth C. Goulter ◽  
Jodie L. Green ◽  
Donald J. Maclean ◽  
...  

An antimicrobial peptide (HvAMP1) was isolated from seeds of the Australian native legume Hardenbergia violacea (Schneev.) Stearn. The peptide is 47 amino acid residues in length, contains 8 cysteines, and has a molecular weight of 5392 and a predicted pI of 10.41. HvAMP1 inhibited the growth of several plant pathogenic fungi at concentrations as low as 1 µM in vitro and produced distinct hyphal distortion and increased branching. This antimicrobial activity was greatly diminished in the presence of 1 mM CaCl2 and 50 mM KCl. The purified peptide at 40 µM did not inhibit three different a-amylase enzymes. Aeukaryotic cell-free translation system showed inhibition approaching 50% in the presence of ~100 µM of HvAMP1. The viability of plant and mammalian cells cultured in vitro was not adversely affected by concentrations of HvAMP1 as high as 40 mM. The amino acid sequence of HvAMP1 contained the consensus amino acids that define the plant defensin family of peptides. The HvAMP1 amino acid sequence showed 87% and 57% identity with the amino acid sequences deduced from cDNA sequences from defensins of Vigna unguiculata and Pisum sativum, respectively. Other plant defensin sequences showed less than 33% amino acid identity to the peptide. Therefore, HvAMP1 and the putative plant defensins of cowpea and pea define a distinct sequence subfamily of plant defensins which is at present limited to members of the Fabaceae. HvAMP1 is the first member of this subfamily to be purified and functionally characterised. The antimicrobial activity of HvAMP1 suggests a defensive role for this subfamily of peptides.


Author(s):  
M.K. Lamvik ◽  
L.L. Klatt

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.


1989 ◽  
Vol 61 (03) ◽  
pp. 437-441 ◽  
Author(s):  
Cindra Condra ◽  
Elka Nutt ◽  
Christopher J Petroski ◽  
Ellen Simpson ◽  
P A Friedman ◽  
...  

SummaryThe present work reports the discovery and charactenzation of an anticoagulant protein in the salivary gland of the giant bloodsucking leech, H. ghilianii, which is a specific and potent inhibitor of coagulation factor Xa. The inhibitor, purified to homogeneity, displayed subnanomolar inhibition of bovine factor Xa and had a molecular weight of approximately 15,000 as deduced by denaturing SDS-PAGE. The amino acid sequence of the first 43 residues of the H. ghilianii derived inhibitor displayed a striking homology to antistasin, the recently described subnanomolar inhibitor of factor Xa isolated from the Mexican leech, H. officinalis. Antisera prepared to antistasin cross-reacted with the H. ghilianii protein in Western Blot analysis. These data indicate that the giant Amazonian leech, H. ghilianii, and the smaller Mexican leech, H. officinalrs, have similar proteins which disrupt the normal hemostatic clotting mechanisms in their mammalian host’s blood.


1993 ◽  
Vol 69 (03) ◽  
pp. 217-220 ◽  
Author(s):  
Jonathan B Rosenberg ◽  
Peter J Newman ◽  
Michael W Mosesson ◽  
Marie-Claude Guillin ◽  
David L Amrani

SummaryParis I dysfibrinogenemia results in the production of a fibrinogen molecule containing a functionally abnormal γ-chain. We determined the basis of the molecular defect using polymerase chain reaction (PCR) to amplify the γ-chain region of the Paris I subject’s genomic DNA. Comparative sequence analysis of cloned PCR segments of normal and Paris I genomic DNA revealed only an A→G point mutation occurring at nucleotide position 6588 within intron 8 of the Paris I γ-chain gene. We examined six normal individuals and found only normal sequence in this region, indicating that this change is not likely to represent a normal polymorphism. This nucleotide change leads to a 45 bp fragment being inserted between exons 8 and 9 in the mature γparis I chain mRNA, and encodes a 15 amino acid insert after γ350 [M-C-G-E-A-L-P-M-L-K-D-P-C-Y]. Alternative splicing of this region from intron 8 into the mature Paris I γ-chain mRNA also results after translation into a substitution of S for G at position γ351. Biochemical studies of 14C-iodoacetamide incorporation into disulfide-reduced Paris I and normal fibrinogen corroborated the molecular biologic predictions that two additional cysteine residues exist within the γpariS I chain. We conclude that the insertion of this amino acid sequence leads to a conformationallyaltered, and dysfunctional γ-chain in Paris I fibrinogen.


1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.


Diabetes ◽  
1980 ◽  
Vol 29 (10) ◽  
pp. 782-787 ◽  
Author(s):  
F. M. Ng ◽  
J. Bornstein ◽  
C. E. Pullin ◽  
J. O. Bromley ◽  
S. L. Macaulay

2020 ◽  
Author(s):  
Michele Larocca

<p>Protein folding is strictly related to the determination of the backbone dihedral angles and depends on the information contained in the amino acid sequence as well as on the hydrophobic effect. To date, the type of information embedded in the amino acid sequence has not yet been revealed. The present study deals with these problematics and aims to furnish a possible explanation of the information contained in the amino acid sequence, showing and reporting rules to calculate the backbone dihedral angles φ. The study is based on the development of mechanical forces once specific chemical interactions are established among the side chain of the residues in a polypeptide chain. It aims to furnish a theoretical approach to predict backbone dihedral angles which, in the future, may be applied to computational developments focused on the prediction of polypeptide structures.</p>


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