human growth hormone;
mutation;
proteolytic insensitivity;
plasmin;
thrombin;
human plasma;
D O I:
10.1016/S0168-1656(98)00113-8
中图分类号:
Q81 [生物工程学(生物技术)];
Q93 [微生物学];
学科分类号:
071005 ;
0836 ;
090102 ;
100705 ;
摘要:
The region having a sequence from amino acid 134 to 150 in human growth hormone (hGH) is known to be cleaved by proteases in human plasma, plasmin and thrombin. In this study, oligonucleotide primer-directed mutagenesis was used to produce recombinant mutant hGHs resistant to limited proteolysis by these proteases. Substitution of Arg(134) and Thr(135) of hGH with Asp(134) and Pro(135) yielded a thrombin-resistant hGH mutant: and substitution of Arg(134), Thr(135) and Lys(140) With Asp(134), Pro(135) and Ala(140) yielded a plasmin-resistant hGH mutant. The latter mutant hGH was also insensitive to in vitro proteolysis by human plasma incubated for 7 days. These alterations in amino acid residues of hGH did not disrupt its biological conformation and retained full growth promoting activities on rat Nb2 cells and human T-47D breast cancer cells. (C) 1998 Elsevier Science B.V. All rights reserved.