Role of basic amino acids in the interaction of bindin with sulfated fucans.
Role of basic amino acids in the interaction of bindin with sulfated fucans.
复制标题
碱性氨基酸在结合蛋白与硫酸化岩藻聚糖相互作用中的作用。
DOI：
10.1021/bi00421a030
复制
发表时间：
1988
期刊：
影响因子：
2.9
通讯作者：
Glabe,CG
中科院分区：
文献类型：
--
作者：
DeAngelis,PL;Glabe,CG
加州大学欧文分校分子生物学和生物化学系Paul L.DeAngelis和Charles G.Glabe**于1988年4月19日收到修订稿，1988年6月30日收到修订稿件摘要：Bindin是海胆Strongyloctus Puratus的顶体精子黏附蛋白，在高离子强度的海水(0.55M盐)环境中与卵子硫酸岩藻糖特异结合，亲和力高(ALD=10~8M)。以前的研究表明，多糖中带负电荷的硫酸盐基团是结合的关键，这表明结合机制涉及结合素的碱性残基。我们发现，在海水的离子强度下，褐藻糖胶与结合素或多聚精氨酸的结合是稳定的，而褐藻糖胶与聚赖氨酸或多组氨酸的结合在该离子强度下被抑制50%或更多。精氨酸、赖氨酸或结合素组氨酸残基的基团特异性修饰导致岩藻糖胶结合活性的显著失活。用岩藻胶预孵育可以几乎完全保护结合素不被精氨酸特异性试剂丁二酮和苯乙醛灭活，但只能适度减缓组氨酸试剂焦碳酸二乙酯的失活。相反，先前的岩藻糖胶结合不能阻止柠檬酸酐与赖氨酸残基反应而失去活性。在修饰前的预孵育过程中，当使用的多糖是岩藻多糖量的800-3000倍时，其他与结合素相互作用不强的硫酸酯多糖不能保护结合不受苯乙醛介导的失活。我们发现更大、更疏水性的精氨酸修饰剂，樟脑酚-10-磺酸和环己二酮，不能灭活岩藻糖胶结合，这表明必需的精氨酸残基可能存在于这些试剂接触受限的环境中。监测[14C]苯乙醛掺入和岩藻胶结合失活的平行动力学研究表明，四个总精氨酸残基中的几个可能是岩藻胶结合的关键。我们认为，结合基精氨酸胍部分可能与硫酸酯形成环状、共振的氢键体系，精氨酸残基与硫酸酯在不同的多糖结构上的互补取向可能决定了观察到的多糖与结合素结合的特异性。
Paul L. DeAngelis and Charles G. Glabe** Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California 92717 Received April 19, 1988; Revised Manuscript Received June 30, 1988 abstract: Bindin, the acrosomalsperm adhesion protein of the sea urchin Strongylocentrotus purpuratus, binds specifically and with high affinity (Ald= 10~ 8 M) to egg sulfated fucans in the high ionic strength milieu of seawater (0.55 M salt). Previous studies indicated that the negatively charged sulfate groups of the polysaccharide are critical for bindingwhich suggested a binding mechanism involving basicresidues of bindin. Wefound that the binding of fucan to bindin or polyarginine is stable at the ionic strength of seawater, whereas the binding of fucan to polylysine or polyhistidine is inhibited by 50% or more at this ionic strength. Group-specific modification of either arginine, lysine, or histidine residues of bindin results in a substantial inactivation of fucan binding activity. Preincubation of bindin with fucan can almost completely protect bindin from inactivation by arginine-specific reagents, butanedione and phenylglyoxal, but only moderately slowed the inactivation by the histidine reagent diethyl pyrocarbonate. In contrast, prior fucan binding could not prevent loss of activity by the reaction of citraconic anhydride with lysine residues. Other sulfated polysaccharides which do not interact strongly with bindin did not protectbinding from phenylglyoxal-mediated inactivation when 800-3000-fold more polysaccharide than fucan was used during the preincubation before modification. We found that the larger and more hydrophobic argininemodifying reagents, camphorquinone-10-sulfonic acid and cyclohexanedione, fail to inactivate fucan binding, suggesting that essential arginine residues may reside in an environment with restricted accessibility to these reagents. Parallel kinetic studies monitoring [14C] phenylglyoxal incorporation and fucan binding inactivation indicate that several of the four total arginine residues may be critical for fucan binding. We suggest that the bindin arginine guanido moieties may form cyclic, resonating hydrogen-bonding systems with sulfate esters and the complementary orientation of the arginine residues in relationship to the sulfate esters on the various polysaccharide structures may determine the observed specificity of polysaccharide binding to bindin.