Localization of glyceraldehyde-3-phosphate dehydrogenase in intact human erythrocytes. Evaluation of membrane adherence is autoradiographs at low grain density.

Human erythrocytes were treated with highly tritiated [3H]iodoacetate under conditions when half of the label became attached to glyceraldehyde-3-phosphate dehydrogenase. After fixation, the cells were subjected to electron microscopic autoradiography. For the evaluation of distribution of grains, which were relatively few, a computerized method was developed. Statistical analysis of data showed the significant adherence of grains to the cell membrane. The results support the view that glyceraldehyde-3-phosphate dehydrogenase is localized near the membrane in the intact erythrocyte.