DIMERIZATION OF HUMAN GROWTH-HORMONE BY ZINC
DIMERIZATION OF HUMAN GROWTH-HORMONE BY ZINC
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DOI：
10.1126/science.1907025
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发表时间：
1991-08-02
期刊：
影响因子：
56.9
通讯作者：
WELLS, JA
中科院分区：
文献类型：
--
作者：
CUNNINGHAM, BC;MULKERRIN, MG;WELLS, JA
分子排阻色谱和沉降平衡研究表明，锌离子（Zn 2+）可诱导人生长激素（hGH）的二聚化。Zn-65（2+）与hGH结合的Scatchard分析表明，hGH的每个二聚体中有两个Zn+离子以协同方式缔合。钴（II）可以取代激素二聚体中的Zn 2+，并给出了由含氧和含氮配体以四面体方式配位的钴的可见光谱特征。用丙氨酸取代hGH中潜在的Zn 2+配体（His 18、His 21和Glu 174），可减弱Zn 2+结合和hGH二聚体形成。Zn+-hGH二聚体在盐酸胍中变性时比单体hGH更稳定。形成的Zn 2 +-hGH二聚体复合物可能是重要的hGH在分泌颗粒中的存储。
Size-exclusion chromatography and sedimentation equilibrium studies demonstrated that zinc ion (Zn 2+) induced the dimerization of human growth hormone (hGH). Scatchard analysis of Zn-65(2+) binding to hGH showed that two Zn+ ions associate per dimer of hGH in a cooperative fashion. Cobalt (II) can substitute for Zn2+ in the hormone dimer and gives a visible spectrum characteristic of cobalt coordinated in a tetrahedral fashion by oxygen- and nitrogen-containing ligands. Replacement of potential Zn2+ ligands (His 18, His 21, and Glu 174) in hGH with alanine weakened both Zn2+ binding and hGH dimer formation. The Zn+-hGH dimer was more stable than monomeric hGH to denaturation in guanidine-HCl. Formation of a Zn2+-hGH dimeric complex may be important for storage of hGH in secretory granules.