Biosynthetic 20-kilodalton methionyl-human growth hormone has diabetogenic and insulin-like activities.
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| Abstract |
The anterior pituitary gland produces a 20-kilodalton (kDa) variant of human growth hormone (hGH) that differs from the predominant 22-kDa form of hGH in that amino acid residues 32-46 are deleted. Previous work has suggested that the 20-kDa variant possesses the full growth-promoting and lactogenic activities of 22-kDa hGH but lacks its intrinsic diabetogenic and insulin-like activities. In the present study, recombinant DNA techniques were used to prepare biosynthetic 20-kDa hGH, and some of the biological properties of the purified hGH variant were examined. The biosynthetic 20-kDa hGH variant was found to share the propensity for aggregation exhibited by its native counterpart. Moreover, like the native variant, biosynthetic 20-kDa hGH possessed full growth-promoting activity in the weight gain test in hypophysectomized rats. However, contrary to previous work suggesting that native 20-kDa hGH lacks diabetogenic and insulin-like activities, biosynthetic 20-kDa hGH was found to have substantial diabetogenic activity when administered chronically to ob/ob mice and to possess approximately 20% the in vitro insulin-like activity of biosynthetic 22-kDa hGH on isolated epididymal adipose tissue of hypophysectomized rats. The diabetogenic and insulin-like activities of biosynthetic 20-kDa hGH cannot be ascribed to contamination of the hormone preparation with the 22-kDa form of hGH or with other diabetogenic or insulin-like pituitary peptides. Therefore, the results strongly suggest that diabetogenic and insulin-like activities are also intrinsic properties of the 20-kDa variant of hGH.
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| Authors | J L Kostyo, C M Cameron, K C Olson, A J Jones, R C Pai |
| Journal | Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 82 Issue 12 Pg. 4250-3 (Jun 1985) ISSN: 0027-8424 [Print] United States |
| PMID | 3889926 (Publication Type: Journal Article) |
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