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Modification of Protein Properties by Change in Charge.
- Source :
- European Journal of Biochemistry; 1972, Vol. 29 Issue 2, p377-385, 9p
- Publication Year :
- 1972
-
Abstract
- Succinylated derivatives of bovine chymotrypsinogen A and α-chymotrypsin were prepared by treatment of the native proteins with succinic anhydride; 60% of the 6-amino groups of the 13 lysine residues form stable succinylated products. The large negative charge at neutral pH is reflected in electrophoretic and titration behavior but absorption spectra, rotatory-dispersion spectra and reversible unfolding behavior indicate that the succinylated species are conformationally similar to the parent proteins. Succinylated chymotrypsin is active as an esterase with N-acetyl-L-tryptophan ethyl ester with a small decrease in the maximum-velocity parameter. The pH dependence suggests that three ionizing groups influence catalytic behavior. The apparent pK<subscript>a</subscript> values analyzed in terms of three groups are shifted relative to α-chymotrypsin. Thermal-unfolding studies of succinylated chymotrypsinogen demonstrate the presence of substrates near pH 7 but is consistent with two-state behavior at other pH values. [ABSTRACT FROM AUTHOR]
- Subjects :
- PROTEINS
ANHYDRIDES
CHYMOTRYPSIN
ELECTROPHORESIS
ELECTROCHEMISTRY
BIOCHEMISTRY
Subjects
Details
- Language :
- English
- ISSN :
- 00142956
- Volume :
- 29
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- European Journal of Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 12513019
- Full Text :
- https://doi.org/10.1111/j.1432-1033.1972.tb01999.x