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A novel family of small cysteine-rich antimicrobial peptides from seed of Impatiens balsamina is derived from a single precursor protein.

Authors :
Tailor, R H
Acland, D P
Attenborough, S
Cammue, B P
Evans, I J
Osborn, R W
Ray, J A
Rees, S B
Broekaert, W F
Source :
Journal of Biological Chemistry; September 1997, Vol. 272 Issue: 39 p24480-7, 8p
Publication Year :
1997

Abstract

Four closely related peptides were isolated from seed of Impatiens balsamina and were shown to be inhibitory to the growth of a range of fungi and bacteria, while not being cytotoxic to cultured human cells. The peptides, designated Ib-AMP1, Ib-AMP2, Ib-AMP3, and Ib-AMP4, are 20 amino acids long and are the smallest plant-derived antimicrobial peptides isolated to date. The Ib-AMPs (I. balsamina antimicrobial peptides) are highly basic and contain four cysteine residues which form two intramolecular disulfide bonds. Searches of protein data bases have failed to identify any proteins with significant homology to the peptides described here. Characterization of isolated cDNAs reveals that all four peptides are encoded within a single transcript. The predicted Ib-AMP precursor protein consists of a prepeptide followed by 6 mature peptide domains, each flanked by propeptide domains ranging from 16 to 35 amino acids in length. Such a primary structure with repeated alternating basic mature peptide domains and acidic propeptide domains has, to date, not been reported in plants.

Details

Language :
English
ISSN :
00219258 and 1083351X
Volume :
272
Issue :
39
Database :
Supplemental Index
Journal :
Journal of Biological Chemistry
Publication Type :
Periodical
Accession number :
ejs7209463