Olli Sudar, Kirti P B
Department of Plant Sciences, School of Life Sciences, University of Hyderabad, India.
J Biochem Mol Biol. 2006 May 31;39(3):278-83. doi: 10.5483/bmbrep.2006.39.3.278.
Defensins are small cysteine rich peptides with a molecular mass of 5-10 kDa and some of them exhibit potent antifungal activity. We have cloned the coding region of a cDNA of 225 bp cysteine rich defensin, named as Tfgd1, from the legume Trigonella foenum-graecum. The amino acid sequence deduced from the coding region comprised 74 amino acids, of which the N-terminal 27 amino acids constituted the signal peptide and the mature peptide comprised 47 amino acids. The protein is characterized by the presence of eight cysteine resisdues, conserved in the various plant defensins forming four disulphide bridges, which stabilize the mature peptide. The recombinant protein expressed in E coli exhibited antifungal activity against the broad host range fungus, Rhizoctonia solani and the peanut leaf spot fungus, Phaeoisariopsis personata.
防御素是一类富含半胱氨酸的小分子肽，分子量为5-10 kDa，其中一些具有强大的抗真菌活性。我们从豆科植物胡芦巴中克隆了一个225 bp富含半胱氨酸的防御素cDNA编码区，命名为Tfgd1。从编码区推导的氨基酸序列由74个氨基酸组成，其中N端的27个氨基酸构成信号肽，成熟肽由47个氨基酸组成。该蛋白的特征是存在八个半胱氨酸残基，在各种植物防御素中保守，形成四个二硫键，稳定成熟肽。在大肠杆菌中表达的重组蛋白对广谱宿主范围真菌立枯丝核菌和花生叶斑病菌人拟茎点霉具有抗真菌活性。
