Formation of isoaspartate at two distinct sites during in vitro aging of human growth hormone

In vitro aging at pH 7.4, 37 degree C causes natural sequence recombinant human growth hormone (rhGH), methionyl rhGH, and human pituitary growth hormone to become substrates for bovine brain protein carboxyl methyltransferase, an enzyme that modifies the "side chain" alpha -carboxyl group...

Full description

Saved in:
Bibliographic Details
Published inThe Journal of biological chemistry Vol. 264; no. 24; pp. 74262 - 74271
Main Authors Johnson, BA, Shirokawa, J M, Hancock, W S, Spellman, M W, Basa, L J, Aswad, D W
Format Journal Article
LanguageEnglish
Published 01.01.1989
Subjects
isoaspartic acid
man
Online AccessGet full text

Cover

More Information
Summary:In vitro aging at pH 7.4, 37 degree C causes natural sequence recombinant human growth hormone (rhGH), methionyl rhGH, and human pituitary growth hormone to become substrates for bovine brain protein carboxyl methyltransferase, an enzyme that modifies the "side chain" alpha -carboxyl group present at atypical isoaspartyl linkages. The substrate capacity of rhGH increased at a rate of 1.8 methyl-accepting sites/day/100 molecules of hormone. Reversed-phase high performance liquid chromatography (HPLC) of trypsin digests of aged rhGH revealed two altered peptides not present in digests of control rhGH.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
content type line 23
ObjectType-Feature-2
ISSN:0021-9258