Factors Affecting Cyanoborohydride Reduction of Aromatic Schiff’s Bases in Proteins
Reductive alkylation of bovine serum albumin (BSA) and wool by aromatic aldehydes and sodium cyanoborohydride has been investigated. The aldehydes used were chosen to allow convenient quantitative measurement of binding by ultraviolet spectroscopy. Alkylation of BSA occurred primarily at two highly reactive sites. Variation of time, pH, reactant concentration, and addition of urea had little effect on the extent of alkylation of BSA. However, more extensive alkylation was achieved in buffered aqueous dimethyl sulfoxide. The unusual reactivity of two γ-amino groups on the BSA molecule is attributed to closely placed lysine residues in the primary sequence rather than to favorable placement of unrelated, distant reactive centers. Similarly, only a few of the potentially available γ-amino groups of wool were observed to react.
KeywordsAromatic Aldehyde Bovine Serum Albumin Molecule Sodium Cyanoborohydride Reductive Alkylation Pyridine Carboxaldehyde
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- Broderick, C. A. (1975). Factors affecting ruminant responses to protected amino acids and proteins, In “Protein Nutritional Quality of Foods and Feeds,” M. Friedman (Editor), Dekker, New York, Part 2, pp. 211–259. cf. also papers by Broderick and by Friedman and Broderick, this volume.Google Scholar
- Edsall, J. T. and Wyman, J. (1958). “Biophysical Chemistry,” Vol. 1, Academic Press, Inc., New York, pp. 457–463.Google Scholar
- Means, G. E. and Feeney, R. E. (1971). “Chemical Modification of Proteins, ” Holden-Day, Inc., San Francisco, pp. 132–134.Google Scholar