A study of the purification and properties of tryptophan synthetase of Bengal gram (Cicer arietinum)

Nair, Madhusudanan P and Vaidyanathan, CS (1964) A study of the purification and properties of tryptophan synthetase of Bengal gram (Cicer arietinum). In: Archives of Biochemistry and Biophysics, 104 (3). pp. 405-415.

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Abstract

Active preparations of tryptophan synthetase were obtained from Bengal gram (Cicer arietinum) by the following procedure: (1) precipitation of inactive materials by manganous sulfate, (2) Adsorption of impurities on Alumina Cγ, (3) Adsorption of tryptophan synthetase on tricalcium phosphate gel, removal of inert protein from the gel by treatment with phosphate buffer (pH 7.2), and selective elution of the enzyme by 0.15 M phosphate buffer pH 7.2 containing 10% ammonium sulfate and 10−3 M serine. A 220-fold purification of the enzyme with 44% recovery of the activity was achieved. The pH optimum, effect of temperature, and substrate concentration and other properties of the purified enzyme have been studied in detail. Only the Image -isomer of serine takes part in the reaction. The Km values for indole, Image -serine, and Image -serine were calculated to be 0.66, 4.1, and 8.6 × 10−4 M, respectively. A kinetic study of the inhibition of tryptophan synthetase by indole-propionic acid has shown that it is of a competitive type. It has been demonstrated for the first time that 4-nitro-salicylaldehyde can replace pyridoxal phosphate as a coenzyme for the tryptophan synthetase reaction.

Item Type:	Journal Article
Publication:	Archives of Biochemistry and Biophysics
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	24 May 2010 07:16
Last Modified:	19 Sep 2010 06:07
URI:	http://eprints.iisc.ac.in/id/eprint/28092

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