Carnitine Palmityltransferase and its Relation to Palmityl-CoA Synthetase in Blood Platelets from Fasting, Healthy Subjects

Abstract

Carnitine palmityltransferase was assayed in homogenates of human blood platelets by two methods: 1) Incorporation of radioactive carnitine into palmityl-carnitine in the presence of CoA, and 2) the formation of palmityl-carnitine from palmitate, CoA, radioactive carnitine and ATP in the presence of endogenous palmityl-CoA synthetase. Method 2 gave a reliable assay of the activity, which in 8 healthy, fasting subjects was 2.6 ± 1.0 nmol (mean ± S.D.) palmityl-carnitine formed per min per 10⁹ platelets (about 0.16 ± 0.06 U/g wet cells). The activity of palmityl-CoA synthetase was 11.1 ± 3.5 nmol (mean ± S.D.) per min per 10⁹ platelets (about 0.7 ± 0.2 U/g wet platelets). There was a significant correlation between the activity of carnitine palmityltransferase and the activity of palmityl-CoA synthetase.

Key Words:

• Blood platelets
• human
• blood platelet protein
• carnitine palmityl-transferase
• enzyme activity
• enzyme assay
• palmityl-CoA synthetase
• specific enzyme activity