IMMUNOCHEMISTRY OF SPERM WHALE MYOGLOBIN .V. SPECIFIC MODIFICATION OF METHIONINE RESIDUES WITH BETA-PROPIOLACTONE

Apomyoglobin was modified specifically at the two methionine residues by reaction with β-propiolactone. The myoglobin derivative prepared by recombination of modified apomyoglobin with ferriheme possessed spectral and sedimentation properties that were similar to those of the native protein. Also the conformational parameters were identical. With antisera to the native protein modified, recombined myoglobin and recombined controls showed equal antigenic reactivities. Similarly equal antigenic reactivities were obtained with antisera to the modified, recombined protein. The latter reaction could not inhibited with an excess of the carboxyethyl sulfonium salt of methionine. The results confirm that the methionine residues (at positions 55 and 131) are not located in antigenic reactive regions in myoglobin. © 1969.