A note on stability of purified enzymes to dehydration

Highly purified enzymes from commercial sources were dried from aqueous solutions over CaCl₂ or CaSO₄ at 25° c, 4° c or −4° C. Several heat stable enzymes containing SS groups (chymotrypsin, lipase, pepsin and trypsin) retained most of their activity following drying while papain and ribonuclease retained about one-fourth of their original activity. Most SH containing enzymes lost most if not all activity during drying (catalase, hexokinase, glucose and xanthine oxidases, alcohol, glutamate, isocitrate and glucose-6-phosphate dehydrogenases). Lactic dehydrogenase was the exception in this group retaining 75% of its original activity after drying. Neither sucrose nor mannitol were effective in protecting ribonuclease against inactivation during drying. Temperature during drying had little effect on inactivation.