自絮凝酵母细胞膜脂肪酸影响乙醇激活ATP酶  

Fatty Acid Composition of Plasma Membrane Affects in Vivo Ethanol Activation of ATPase in a Self-Flocculating Yeast

作　　者：胡纯铿[1] 白凤武[2] 安利佳[2] 

机构地区：[1]华侨大学材料科学与工程学院,福建泉州362011 [2]大连理工大学环境与生命学院,辽宁大连116024

出　　处：《华侨大学学报（自然科学版）》2005年第3期251-254,共4页Journal of Huaqiao University(Natural Science)

基　　金：国家863高科技研究发展计划基金资助项目(2002AA647060)

摘　　要：首次揭示酵母菌细胞膜磷脂脂肪酸组成对影响质膜ATP酶对乙醇刺激的响应.实验结果表明,细胞膜磷脂脂肪酸组成特点,对生长于未添加乙醇条件下的自絮凝酵母的质膜ATP酶活性没有影响,但却明显影响生长于添加乙醇(体积分数为0.01～0.10)的菌体质膜ATP酶对乙醇激活的敏感性.预培养于添加0.6 mmol·L-1棕榈酸、亚油酸或亚麻酸条件下,菌体质膜ATP酶的最大激活水平分别为各自酶的基态水平(未激活)的3.6,1.5和1.2倍,而对照组(预培养于未添加脂肪酸条件下的菌体)的相应值为2.3倍.酶激活后,米氏常数Km、最适pH和对质膜ATP酶特异性抑制剂钒酸钠的敏感性等性质不变,但最大反应速度Vmax明显增加.实验结果还表明,细胞膜磷脂脂肪酸组成特点对提高菌体的耐乙醇能力越有利,其质膜ATP酶被乙醇激活的幅度越大,说明菌体耐乙醇能力的提高,与其质膜ATP酶对乙醇激活的敏感性的增加密切相关.This work reveals for the first time that fatty acid composition of phospholipids in plasma membranes of yeast significantly affects the response of plasma membrane ATPase to ethanol stimuli. As shown experimentally, the characteristics of phospholipid fatty acid composition of plasma membranes significantly affected the sensitivities of plasma membrane ATPases to in vivo ethanol activation for a self-flocculating yeast growing in the presence of ethanol(volume fraction is 0.01~0.10), although they had no effect on the activities of the enzymes of the cells growing in the absence of ethanol. The maximal levels of activated plasma membrane ATPases for the cells culturing in advance in the presence of 0.6 mmol·L -1 palmitic, linoleic or linolenic acid were 3.6, 1.5 or 1.2-fold higher than the basal(inactivated) levels respectively, while 2.3-fold was the corresponding value for the control(cells culturing in advance in the absence of fatty acid). After enzyme activation, the K _m values, the optimal pH values and the sensitivities of plasma membrane ATPases to specific inhibitor sodium orthovanadate kept constant but V _ max increased significantly. As also shown experimentally, the more advantageous for the characteristics of phospholipid fatty acid composition of plasma membranes to enhance ethanol tolerance of yeast, the greater in vivo ethanol activation of plasma membrane ATPases. This illustrates a close correlation between the enhancement in ethanol tolerance of yeast and the increase in sensitivities of plasma membrane ATPase to in vivo ethanol activation.

关 键 词：耐乙醇 质膜ATP酶 磷脂脂肪酸 自絮凝酵母 米氏常数 

分 类 号：Q550.4[生物学—生物化学] Q936