Reaction of myoglobin with 3,3-tetramethyleneglutaric anhydride.

1. The extent of reaction of the protein with 3,3-tetramethyleneglutaric anhydride was measured by determining the loss of lysine and the equivalent appearance of 3,3-tetramethyleneglutarimidolysine in the hydrolysate at various time-intervals. Of the 19 lysine residues in sperm-whale myoglobin, three did not react with 3,3-tetramethyleneglutaric anhydride. Also, the N-terminal valine did not react. 2. Slight spectral changes were observed on modification of myoglobin. 3. Electrophoretic changes were great since the derivative was negative throughout the range pH6-8.8. 4. The derivative did not react with antisera to native sperm-whale myoglobin.