Involvement of Vitamin B
            <sub>6</sub>
            in the Dethiomethylation of Methionine by Rumen Microorganisms

Merricks, D. L.; Salsbury, R. L.

doi:10.1128/am.28.1.106-111.1974

Cited by 8 publications

(1 citation statement)

References 10 publications

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“…L-Methionine 7-lyase was subsequently demonstrated in extracts of a soil bacterium (Mitsuhashi and Matsuo, 1950), Pseudomonas sp. (Miwatani et al, 1954;Kallio and Larson, 1955), Clostridium sporogenes (Wiesendanger and Nisman, 1953), rumen bacteria (Merricks and Salsbury, 1974), Ps. ovalis (Tanaka et al, 1974), and Ps.…”

Section: -Lyasementioning

confidence: 99%

Properties of L-methionine γ-lyase from Pseudomonas ovalis

Tanaka¹,

Esaki²,

Soda³

1977

Biochemistry

145

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The distribution of bacterial L-methionine gamma-lyase (L-methionine methanethiollyase (deaminating) (EC 4.4.1.11) was investigated, and Pseudomonas ovalis (IFO 3738) was found to have the highest activity of enzyme, which was inducibly formed by addition of L-methionine to the medium. L-Methionine gamma-lyase, purified to homogeneity from Ps. ovalis, has a molecular weight of about 173 000 and consists of nonidentical subunits (mol wt: 40 000 and 48 000). The enzyme exhibits absorption maxima at 278 and 420 nm, and a shoulder around 330 nm, which are independent of the pH (6.0 to 10.0), and contains 4 mol of pyridoxal 5'-phosphate per mol of the enzyme. The formyl group of pyridoxal 5'-phosphate is bound in an aldimine linkage to the epsilon-amino group of lysine residues of the protein. The holoenzyme is resolved to the apoenzyme by incubation with hydroxylamine, and reconstituted by addition of pyridoxal 5'-phosphate. The enzyme activity is significantly affected by both carbonyl and sulfhydryl reagents. L-Methionine gamma-lyase catalyzes alpha,gamma- and alpha,beta-elimination reactions of, in addition to L-methionine, several derivatives of L-methionine and L-cysteine, e.g., L-ethionine, DL-methionine sulfone, L-homocysteine, and S-methyl-L-cysteine. The enzyme catalyzes also gamma-replacement reactions of the thiomethyl group of methionine with various alkanethiols (C2-C7), arylthio alcohols (benzenethiol and beta-naphthalenethiol) and the derivatives of ethanethiol (2-mercaptoethanol and cysteamine) to yield the corresponding S-substituted homocysteine. The thiomethyl group of S-methyl-L-cysteine also is replaced by ethanethiol to form S-ethyl-L-cysteine.

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Section: -Lyasementioning

confidence: 99%