The Activity of an Enzyme in the Crystalline State: Ribonuclease S

Some Specific Ion Effects on the Conformation and Thermal Stability of Ribonuclease*

“…In this regard, the results of Kalnitsky and Resnick (1959) indicate that RNA, in contrast to the small specific anions and perhaps the pyrimidine 2',3'-cyclic phosphates, destabilizes the ribonuclease molecule, and this could arise from an interaction of RNA with other side-chain groups of ribonuclease. Doscher and Richards (1963) found that crystalline suspensions of ribonuclease S in concentrated ammonium sulfate solutions are catalytically active toward the pyrimidine nucleoside 2 ',3 '-cyclic phosphates. This may be due to the ability of sulfate, which stabilizes configurations more easily crystallizable (Kunitz, 1940), to maintain the correct atomic distances at the active site for catalysis to occur.…”

Comparison of Protein Structure in the Crystal and in Solution. I. The Tyrosyl Ionization of Crystalline Methemoglobin*

“…Banaszak et al (1963) studied the reaction of bromoacetate with the histidines of myoglobin, and found that the same groups reacted in the crystal and solution. Doscher and Richards (1963) have shown that ribonuclease is enzymically active in the crystal, and that only small changes in X-ray diffraction pattern are caused by substrate or inhibitor binding to the crystalline protein. Praissman and Rupley (1964) have studied the tritium-hydrogenexchange behavior of insulin in solution and in the crystal; differences were observed which require explanation in terms of a structural change.…”

Protein crystal based materials for nanoscale applications in medicine and biotechnology

“…Myriad applications for engineered protein crystals depend on transport rates and/or molecular interactions between guest molecules and the pore surfaces of scaffold materials. For instance, enzyme crystal biocatalysis applications are sensitive to the ratio of crystalline pore size to the size of the substrates and products, as mass-transfer rates can limit the net activity for cross-linked enzyme crystals (CLECs) of sufficient size (Chance, Ravilly, & Rumen, 1966;Doscher & Richards, 1963;Quiocho & Richards, 1966). Similarly, in the case of chromatography, the separation capability of protein crystals is dependent on three modes of physical segregation: adsorption, diffusion, and size exclusion-all of which are influenced by mass transport.…”