Publication Date:
1991-08-02
Description:
Size-exclusion chromatography and sedimentation equilbrium studies demonstrated that zinc ion (Zn2+) induced the dimerization of human growth hormone (hGH). Scatchard analysis of 65Zn2+ binding to hGH showed that two Zn2+ 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 (His18, His21, and Glu174) in hGH with alanine weakened both Zn2+ binding and hGH dimer formation. The Zn(2+)-hGH dimer was more stable than monomeric hGH to denaturation in guanidine-HCl. Formation of a Zn(2+)-hGH dimeric complex may be important for storage of hGH in secretory granules.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cunningham, B C -- Mulkerrin, M G -- Wells, J A -- New York, N.Y. -- Science. 1991 Aug 2;253(5019):545-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Protein Engineering, Genentech, South San Francisco, CA 94080.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1907025" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Binding Sites
;
Chromatography, Gel
;
Edetic Acid/pharmacology
;
Growth Hormone/*metabolism
;
Humans
;
Kinetics
;
Macromolecular Substances
;
Models, Molecular
;
Protein Binding
;
Protein Conformation
;
Protein Denaturation
;
Spectrophotometry
;
Zinc/metabolism/*pharmacology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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