Adenosine 3':5'-monophosphate-dependent protein kinase from human placenta: characterization of the catalytic subunit.
The catalytic subunit of cAMP-dependent protein kinase (EC 2.7.1.37) was purified for the first time from human placenta by DEAE-cellulose and HTP chromatography. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis showed a single band of average molecular weight of 42 kDa (SEM = 0.52). Kinetic experiments showed a Km for ATP of 12.6 +/- 1.2 mumol/l, for histone II-AS of 1.3 +/- 0.05 mg.ml-1, for kemptide of 11.4 +/- 4.4 mumol/l. The synthetic inhibitor IP20-amide showed a competitive mechanism of inhibition with a Ki of 5.0 nmol/l. The protein kinase inhibitors H7 and H9 showed an apparent Ki of 8.3 and 4.9 mumol/l respectively. Preparative isoelectric focusing revealed the presence of 5 different isoforms with an average pI of 6.17, 6.70, 7.15, 7.67, 8.9.
Tamanini
A
A
Cystic Fibrosis Center, Verona, Italy.
Berton
G
G
Cabrini
G
G
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000255:Adenosine Triphosphate / Q000378:metabolism; D001665:Binding Sites; D005260:Female; D006801:Humans; D007527:Isoenzymes; D007546:Isoquinolines / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D010920:Placenta / Q000187:drug effects / Q000201:enzymology*; D011247:Pregnancy; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000737:chemistry* / Q000187:drug effects; D013449:Sulfonamides
D007527:Isoenzymes; D007546:Isoquinolines; D009842:Oligopeptides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D013449:Sulfonamides; C037642:kemptide; C044388:N-(2-aminoethyl)-5-isoquinolinesulfonamide; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000255:Adenosine Triphosphate; D011494:Protein Kinases