Abstract
The effect of trypsin on R-binder (R)-cobalamin (Cbl) analogue complexes has been studied using ^<12>Co-labeled cobinamide (Cbi) in comparison with R-cyanocobalamin (CN-Cbl). R-[^<57>Co] Cbi was digested with trypsin in the presence of human intrinsic factor (IF) and guinea pig IF-Cbl receptor, and its elution pattern was examined with a Sephadex G-200 column. Free [^<57>Co] Cbi was released from R-[^<57>Co] Cbi by trypsin, but bound neither to IF nor to IF-Cbl receptor. The release of [^<57>Co] 'Cbi from R-[^<57>Co] 'Cbi was increased by in-creasing amounts of trypsin.
