Premium
A new GTP‐binding protein in brain tissues serving as the specific substrate of islet‐activating protein, pertussis toxin
Author(s) -
Katada Toshiaki,
Oinuma Masayuki,
Kusakabe Kayoko,
Ui Michio
Publication year - 1987
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(87)81521-1
Subject(s) - heterotrimeric g protein , pertussis toxin , g protein , g alpha subunit , gtp binding protein regulators , alpha (finance) , gs alpha subunit , gtp' , protein subunit , gi alpha subunit , beta (programming language) , gamma subunit , biology , adenylate cyclase toxin , biochemistry , microbiology and biotechnology , toxin , enzyme , receptor , medicine , gene , construct validity , nursing , computer science , programming language , patient satisfaction
A new GTP‐binding protein serving as the specific substrate of islet‐activating protein (IAP), pertussis toxin, was purified from porcine brain membranes as an αβγ‐heterotrimeric structure. The α‐subunit of the purified protein (α 40 βγ) had a molecular mass of 40 kDa and differed from that of G i (α 41 βγ) or G o (α 39 βγ) previously purified from brain tissues. The fragmentation patterns of limited tryptic digestion and immunological cross‐reactivities among the three α were different from one another. However, the βγ‐subunit resolved from the three IAP substrates similarly inhibited a membrane‐bound adenylate cyclase and their β‐subunits were immunologically indistinguishable from one another. Thus, the α 40 βγ is a new IAP substrate protein different from G i or G o , in the α‐subunit only.