Interaction of α-agglutinin and a-agglutinin, Saccharomyces cerevisiae sexual cell adhesion molecules
Interaction of α-agglutinin and a-agglutinin, Saccharomyces cerevisiae sexual cell adhesion molecules
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DOI：
10.1128/jb.183.9.2874-2880.2001
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发表时间：
2001-05-01
影响因子：
3.2
通讯作者：
Lipke, PN
中科院分区：
文献类型：
--
作者：
Zhao, H;Shen, ZM;Lipke, PN
α-凝集素和α-凝集素是酵母交配过程中活跃的互补细胞黏附糖蛋白。它们以高亲和力和高特异性结合：相反交配类型的细胞不可逆地被几对凝集素结合。平衡和表面等离子体共振动力学分析表明，纯化的α-凝集素结合区与纯化的α-凝集素以及细胞表面表达的α-凝集素具有相似的相互作用。在20℃时，相互作用的K-D为2×10(-9)~5×10(-9)M，这种高亲和力是由于很低的解离率(约为2.6×10(-4)S(-1))和低缔合率(=5×10(-4)M-1 S(-1))的结果，圆二色谱搁置了蛋白质的结合伴随着可测量的二级结构的变化。此外，当结合温度为10℃时，结合动力学呈S形，初始速率很低，结合的诱导-拟合模型与两个配体上疏水表面的大量贴合可以解释观察到的亲和力、动力学、特异性和结合反应的构象效应。
alpha -Agglutinin and a-agglutinin are complementary cell adhesion glycoproteins active during mating in the yeast Saccharomyces cerevisiae. They bind with high affinity and high specificity: cells of opposite mating types are irreversibly bound by a few pairs of agglutinins. Equilibrium and surface plasmon resonance kinetic analyses showed that the purified binding region of alpha -agglutinin interacted similarly with purified a-agglutinin and with a-agglutinin expressed on cell surfaces. At 20 degreesC, the K-D for the interaction was 2 x 10(-9) to 5 x 10(-9) M, This high affinity was a result of a very low dissociation rate (approximate to 2.6 x 10(-4) s(-1)) coupled with a low association rate (= 5 x 10(4) M-1 s(-1)), Circular-dichroism spectroscopy shelved that binding of the proteins was accompanied by measurable changes in secondary structure. Furthermore, when binding was assessed at 10 degreesC, the association kinetics were sigmoidal, with a very low initial rate, An induced-fit model of binding with substantial apposition of hydrophobic surfaces on the two ligands can explain the observed affinity, kinetics, and specificity and the conformational effects of the binding reaction.