pH值对巴西橡胶树胶乳β-1,3-葡聚糖酶结合黄色体膜的影响  

Effect of pH Value on the Conjunction Betweenβ-1,3-Glucanase and Lutoid Membrane in the Latex of Hevea brasiliensis

作　　者：史敏晶[1,2] 陈月异[1] 田维敏[1] 

机构地区：[1]中国热带农业科学院橡胶研究所农业部橡胶树生物学重点开放实验室省部共建国家重点实验室培育基地-海南省热带作物栽培生理学重点实验室,海南儋州571737 [2]海南大学园艺园林学院,海南儋州571737

出　　处：《热带作物学报》2009年第7期891-896,共6页Chinese Journal of Tropical Crops

基　　金：国家自然科学基金(No.30671712);现代农业产业技术体系建设专项资金(No.nycytx-34-GW1-2);中国热带农业科学院科技基金(No.Rky0606);海南省自然科学基金(No.808189)资助

摘　　要：基于黄色体内含物中的多种可溶性蛋白质以及黄色体膜在胶乳凝固中所起到的重要作用,已提出了多种阐明胶乳凝固机制的假说,但有关β-1,3-葡聚糖酶在胶乳凝固中的作用尚无报导。通过聚丙烯酰胺凝胶电泳(Tricine-SDS-PAGE)和免疫印迹技术(Western blotting),对不同pH值条件下破裂收集的黄色体内含物和膜组分中的蛋白质进行研究。结果表明,在pH5.5左右的酸性环境中,β-1,3-葡聚糖酶主要表现为可溶性蛋白质,很少结合黄色体膜;但在pH6.9左右的中性及偏碱性的环境下,大量β-1,3-葡聚糖酶结合到黄色体膜上,可溶性蛋白所占的比例很低。首次发现了β-1,3-葡聚糖酶可以结合黄色体膜,二者结合的程度明显受环境pH值的影响。该结果对于认识β-1,3-葡聚糖酶的生物功能,完善黄色体在胶乳凝固中的作用及阐明乳管堵塞机制具有重要意义。Several hypotheses for the mechanism by which latex coagulation occurs were raised on the basis of the involvement of soluble protein inclusions and membrane fragments of lutoids in latex coagulation. β-1,3-glucanase in lutoids was never recognized to be related to latex coagulation although its role in defense against pathogen had been well known. The soluble proteins and the membrane-binding proteins of lutoids were extracted with several extraction buffers different in pH value and compositions, and analyzed by Tricine-SDS-PAGE and Western blotting techniques. β-1,3-glucanase was mainly present in the soluble protein fraction when extracted with a buffer solution of about pH 5.5 whereas it was largely bound to the membrane fragments of lutoids in buffer solutions of either neutral or basic pH value, paralleling to an obvious decrease in the level of β-1,3-glucanase in the soluble protein fraction. The conjunction between β-1,3-glucanase and lutoid membrane was pH value-dependent. This paper, for the first time, revealed the binding of β-1,3-glueanase to the lutoid membrane under the condition of physiological pH value in C-serum, which provides a new cue for the plugging formation at the end of severed laticifers.

关 键 词：巴西橡胶树 黄色体膜 β-1 3-葡聚糖酶 Tricine-SDS-PAGE WESTERN BLOTTING 

分 类 号：S794.1[农业科学—林木遗传育种]