Mode of interaction of aminooxy compounds with sheep liver serine hydroxymethyltransferase.

Baskaran, N. and Prakash, V. and Savithri, H. S. and Radhakrishnan, A. N. and Appaji Rao, N. (1989) Mode of interaction of aminooxy compounds with sheep liver serine hydroxymethyltransferase. Biochemistry, 28. pp. 9613-9617.

PDF Biochemistry 1989, 28, 96 13-961 7.pdf - Published Version Restricted to Registered users only Download (613kB) | Request a copy

Abstract

The interaction of aminooxy compounds such as aminooxyacetate (AAA), L-canaline, and hydroxylamine with sheep liver serine hydroxymethyltransferase (EC 2.1.2.1) was studied by absorption spectra and stopped-flow spectrophotometry and compared with the unique feature of interaction of 0- amino-D-serine (OADS) with the enzyme [Baskaran, N., Prakash, V., Appu Rao, A. G., Radhakrishnan, A. N., Savithri, H. S., & Appaji Rao, N. (1989) Biochemistry (preceding paper in this issue)]. The reaction of AAA (0.5 mM) with the Schiff base of the enzyme resulted in the formation of pyridoxal 5'-phosphate (PLP) and was biphasic with rate constants of 191 and 19 s-l. The formation of the PLP-AAA oxime measured by decrease in absorbance at 388 nm on interaction of AAA with the enzyme had a rate constant of 5.2 M-' s-l. On the other hand, the reaction of L-canaline with the enzyme was slower as measured by the disruption of enzyme-Schiff base than the reaction of OADS and AAA. In contrast, the formation of PLP as an intermediate could not be detected upon the interaction of hydroxylamine with the enzyme. The reaction of D-cycloserine with the enzyme was much slower (1.6 X lo2 M-' s-l ) than the aminooxy compounds. These observations indicate that the aminooxy compounds that are structural analogues of serine (OADS, AAA, and canaline) formed PLP as an intermediate prior to the formation of oxime, whereas with hydroxylamine such an intermediate could not be detected.

Item Type:	Article
Uncontrolled Keywords:	aminooxy compounds, sheep liver, serine hydroxymethyltransferase, spectrophotometry
Subjects:	500 Natural Sciences and Mathematics > 07 Life Sciences > 03 Biochemistry & Molecular Biology > 07 Enzyme Biochemistry
Divisions:	Dept. of Biochemistry
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	07 Mar 2018 04:39
Last Modified:	07 Mar 2018 04:39
URI:	http://ir.cftri.res.in/id/eprint/4654

Actions (login required)

View Item