Structural Characterization of the Glycation Process of the Plasma Membrane Calcium Pump

34. GONZÁLEZ FLECHA, F. LUIS, CASTELLO PABLO R., GAGLIARDINO, JUAN J. AND ROSSI, JUAN P.F.C.

ANNALS OF THE NEW YORK ACADEMY OF SCIENCES.

BLACKWELL PUBLISHING

Lugar: Oxford; Año: 1997 vol. 834 p. 126 - 128

0077-8923

We previously showed that the Ca2+-ATPase activity of erythrocytes from poorlycontrolled diabetic patients is significantly lower than that from nondiabetic controlsubjects. This effect was reproduced in vitro by incubation of either intact erythrocytesor erythrocyte membranes with glucose.´ The degree of Ca2+-ATPase inhibitioninduced by in vitro glycation was modified by changes in the incubation media (e.g.,pH increase, presence of phosphates, or replacement of glucose by other reducingsugars), as it generally occurs with the nonenzymatic glycation process.´S2 The kineticbehavior of the decrease in enzymatic activity was identical to that of incorporation of[6-3H]glucose into the purified Ca2+ pump, suggesting that nonenzymatic glycation ofthis protein caused its inactivation.2 This work further characterizes the chemicalreactions involved in the enzymatic inactivation process.