Figure 8.

Half-lives of P-selectins containing conservative and nonconservative amino acid substitutions at position 768. (A) P-selectin cDNAs encoding the indicated amino acid substitutions were expressed in NRK cells. Half-lives were measured after cell surface biotin labeling as described in the legend of Figure 4. All of the indicated substitutions at L768 supported rapid degradation. (B) The indicated P-selectin mutants were expressed in CHO cells. Half-lives were measured after cell surface biotin labeling. Although the L768A mutant exhibited the same long half-life seen in NRK cells, the polar substitution L768N was degraded rapidly.