Abstract
Cytochromes c from two strains of yeast, Saccharomyces oviformis M2 (M2-cyt. c) and Candida krusei, in their cross-reactivities against their antibodies, were investigated by various methods. The results indicated that cytochromes c from these two yeasts cross-reacted each other with their antibodies, but that horse heart cytochrome c did not cross-react. It was also suggested that the passive cutaneous anaphylaxis inhibition test is preferable to the usual in vitro methods in detecting slight difference in the cross-reactivities between closely related antigens. Another experiments using peptide fragments obtained by enzymatic or chemical cleavage of M2-cyt. c showed that P-4 and P-7 were found to fix complements, and P-3, P-4, P-5 and P-6 eliminated the inhibitory effect of the antibody against the enzymatic reaction of cytochrome c-cytochrome oxidase.
