Activation of Inactive Phosphorylase Dimer and Monomer from Human Platelets with Magnesium Adenosine Triphosphate
1969; Elsevier BV; Volume: 244; Issue: 7 Linguagem: Inglês
10.1016/s0021-9258(18)91771-0
ISSN1083-351X
AutoresS Karpatkin, Richard M. Langer,
Tópico(s)Platelet Disorders and Treatments
ResumoAbstract In human platelets, the activity of total phosphorylase could be increased appreciably following incubation with MgATP at 37° for 1 hour or overnight dialysis against MgATP at 4°. The total phosphorylase activity of a 4,000 x g homogenate increased 11-fold following MgATP activation. A 105,000 x g particulate fraction when assayed for phosphorylase activity in the presence of 1 mm AMP was inactive. Following treatment with MgATP at 37° for 1 hour, the fraction gained considerable activity. Sucrose gradient analysis of a 27,000 x g charcoal-treated platelet extract revealed the presence of inactive phosphorylase species with apparent molecular weights of dimer and monomer. These were converted to phosphorylase a as well as phosphorylase b following incubation with MgATP.
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