【摘要】 植物转脂蛋白(LTPs)是多基因编码的蛋白家族,广泛分布于高等植物,其确切的生理功能至今仍不清楚.本室从白菜中分离的钙调素结合蛋白-10(CaMBP10)经序列分析被鉴定为植物转脂蛋白家族成员,体外实验证明钙调素(CaM)调节其脂质结合活性.为了深入了解转脂蛋白与CaM的相互作用机制,本文通过删除、缺失和定点突变等分子生物学手段确定了白菜转脂蛋白CaMBP10分子中的钙调素结合结构域.该结构域位于分子C末端64～83位氨基酸残基之间,其中疏水氨基酸的分布具有1-5-8-10的CaM结合模序特征.更多还原

【Abstract】 Plant non-specific lipid transfer proteins(ns-LTPs) encoded by multigene families are distributed ubiquitously throughout the plant kingdom.Their biological functions in vivo remain unclear.Recently,it has been proposed that ns-LTPs may play a key role in plant defense mechanisms,particularly during the induction of systemic acquired resistance.However,very little was known about the regulation in this process.A CaM-binding protein-10(CaMBP10) isolated from Chinese cabbage,is identified as a new member of lipid transfer protein family.It was found that the lipid-binding activity of CaMBP10 is regulated by CaM in vitro.To understand the interaction between LTPs and CaM,the CaM-binding site of CaMBP10 was mapped to the region of amino acids 64-83 on C-terminal.The point mutations indicated that four amino acid residues,Arg66,Lys72,Lys81 and Lys84,in this region were crucial for binding.And 1-5-8-10 CaM-binding motif was found in this region.Identification and characterization of CaM-binding domain of LTPs should provide new insights into the mechanism by which the physiological functions of LTPs were regulated.更多还原