Sialyltransferase activity of human plasma and aortic intima is enhanced in atherosclerosis.
Sialyltransferase activity has been determined in membrane preparations containing the Golgi apparatus that were isolated from atherosclerotic and normal human aortic intima as well as in plasma of patients with documented atherosclerosis and healthy donors by measuring the transfer of N-acetylneuraminic acid (NeuAc) from CMP-NeuAc to asialofetuin. The asialofetuin sialyltransferase activity was found to be 2 times higher in the atherosclerotic intima as compared to the normal intima and 2-fold higher in patients' plasma than in that from healthy donors. The mean values of the apparent Michaelis constant (K(m)) for the sialylating enzyme for both tissues did not differ and were close for the intima and plasma. In contrast, the maximal velocity (V(max)) was 2 times higher for the atherosclerotic intima than for the normal intima and 3 times higher for patients' plasma than for that of the donors. These results suggest that the activity of asialofetuin sialyltransferases of aortal intima is enhanced in atherosclerosis as is the secretion of their soluble forms into patients' plasma.
Gracheva
Elena V
EV
Institute of Experimental Cardiology, Cardiology Research Center of the Russian Academy of Medical Sciences, 3rd Cherepkovskaya Street, 15A, 121552, Moscow, Russia.
Samovilova
Nelya N
NN
Golovanova
Natalia K
NK
Il'inskaya
Olga P
OP
Tararak
Edward M
EM
Malyshev
Peter P
PP
Kukharchuk
Valery V
VV
Prokazova
Nina V
NV
D000328:Adult; D000368:Aged; D001011:Aorta / Q000201:enzymology* / Q000473:pathology; D001161:Arteriosclerosis / Q000097:blood / Q000201:enzymology* / Q000473:pathology; D001212:Asialoglycoproteins / Q000378:metabolism; D003331:Coronary Vessels / Q000201:enzymology / Q000473:pathology; D005260:Female; D060748:Fetuins; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D012799:Sialyltransferases / Q000378:metabolism*; D017539:Tunica Intima / Q000201:enzymology; D015854:Up-Regulation; D000509:alpha-Fetoproteins / Q000378:metabolism; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase
D001212:Asialoglycoproteins; D060748:Fetuins; D000509:alpha-Fetoproteins; C017029:asialofetuin; D012799:Sialyltransferases; D019158:N-Acetylneuraminic Acid; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase; C000722087:ST3GAL1 protein, human