APPLICATION OF SOLID-STATE CATALYTIC HYDROGEN ISOTOPE-EXCHANGE TO THE TRITIUM LABELING OF LYSOZYME

Solid state catalytic hydrogen isotope exchange has been employed to label hen egg lysozyme with tritium. Optimization of reaction conditions so that amino acids and peptide bonds remained intact led to a tritiated product with 97% of the original enzymatic activity and 94% radiochemical purity. The specific activity when using a T-2:H-2 mixture of 1:1000, was 16 mCi.mmol-(1). It is suggested that the currently adopted approach may have wide applications for other proteins able to tolerate lyophilization conditions without loss of activity.