Structure of crystalline -chymotrypsin. V. The atomic structure of tosyl- -chymotrypsin at 2 A resolution.

Structure of crystalline α-chymotrypsin

STOICHIOMETRY OF SUBUNITS. . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 DISSOCIATION METHODS . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Denaturants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Change of charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Binding of metabolites or s mall ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Reaction with sulfhydryl groups .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 HyBRIDIZATION .... . . . . . . . . . . . . . . . . . . • . . . . . • • • . • . . . . . • . . . .. .... ... .. . 28 TABLE OF SUBUNITS . . . ' " . . . . . . . . . . . . . . . . . . . . . . . • • . . . . . . . ..... ... . .. . 29 GEOMETRIC ARRANGEMENTS OF SUBUNITS 29 CYCLIC SYMMETRY . . . . . . . . . • • . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 DIHEDRAL SYMMETRY . . . . . . . • . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . 36 CUBIC SYMMETRY • • . • . . . . . . • . • . . . . . . . . • . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . 38 GENERAL COMMENTS . . . . . • . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 ENERGETICS OF INTERACTIONS 39 MOLECULAR STRUCTURE OF INTERFACE CONTACTS 52 FACTORS THAT MODIFY SUBUNIT INTERACTIONS S6 INTRINSIC FACTORS . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . • . . . . . . . . . . . . . . . . . • 56 EXTRINSIC FACTORS . . . . . . • • . . . . . . • • . . • . . . • . . . . • . . . . . . . . . . . . . . . . . . . . . . . S7 CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S9

Quaternary Structure of Proteins

To determine the tryptophan content in proteins,an analytical ultraviolet fluroescence method is proposed based on making uniform the environment of aromatic chromophores in 6-7 M guanidine hydrochloride. The fluorescence intensity scale is calibrated using standard solutions of free tryptophan. A correlation coefficient between the fluorescence of protein tryptophanyl residues and of free tryptophan was estimated in testing 17 well characterized proteins. This method is particularly suited to proteins carrying groups absorbing in the 290-370 nm region, such as flavin, heme and pyridoxal phosphate and in the presence of substances such as 2-mercaptoethanol which prohibit the use of the spectroscopic or magnetic circular dichroism methods. It is less time-consuming than techniques requiring hydrolysis or chemical reactions.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1976.tb10228.x

Keisuke Morimoto

Papers

Subunit interactions of lobster hemocyanin: I. Ultracentrifuge studies☆

Dimerization and Activity of Chymotrypsin at pH 4