Figure 3.

Effect of domain cross-linking on CLSS cytochrome c reductase activity. A, indicated CaM-bound proteins were incubated in pH 9 buffer to induce a reversible domain-domain disulfide cross-link in CLSS, and aliquots were removed at the indicated times for activity assay. The CLSS protein was further incubated in neutral buffer with DTT for 3 h, and its activity was assayed to test for reversibility. B, indicated CaM-bound proteins were incubated with NEM or with BMOE to induce a covalent domain-domain cross-link in CLSS, and aliquots were removed at the indicated times for activity assay. Values are the mean ± S.D. of three measurements, representative of two trials.