作者: Mariano Tao , Patricia Hackett
DOI: 10.1016/S0021-9258(19)43605-3
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摘要: Abstract Adenosine cyclic 3':5'-monophosphate (cyclic AMP)-dependent protein kinase from rabbit erythrocytes has been resolved into three active fractions possessing both phosphotransferase and AMP-binding activities. These enzymes are arbitrarily designated as kinases I, IIa, IIb. The kinetic properties substrate specificities of these remarkably similar. All variants catalyze the phosphorylation calf thymus histones stimulated by low concentrations AMP. molecular weights have estimated gel filtration to be 170,000, 120,000, 240,000, corresponding IIb, respectively. differ in temperature (53°) stability. Kinases IIa IIb inactivated more slowly than I. However, rate inactivation I is greatly diminished presence ATP Mg2+. A similar protection compounds not observed with Each appears constructed two dissimilar functional subunits: a catalytic subunit regulatory subunit. Cyclic AMP causes subunits dissociate binding moiety. activation may accomplished protamine. In addition, protamine enhances determined Millipore assay. moiety cross-reacts