• Journal of Microbiology and Biotechnology
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• v.2 no.4
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• pp.260-267
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• 1992

Pectate lyase from alkalitolerant Bacillus sp. YA-14 is an endo-type pectate lyase which acts randomly at the $\alpha$-1, 4-galacturonan linkage, and requires calcium or strontium ions for its activity. The enzyme is active on low methyl esterified pectin, but the activity toward a high methyl esterified substrate is reduced. The apparent Km's of the enzyme toward sodium polygalacturonic acid, polygalacturonic acid, and various pectins such as apple pectin, citrus pectin, and genu pectin are 0.826 mg/ml, 0.685 mg/ml, and 1.14 mg/ml, respectively. The enzyme activity is inhibited by SDS, urea, and sodium azide, but not by various reducing reagents, such as $\beta$-mercaptoethanol, Na-thiosulfate, Na-sulfate, cystein, and L-ascorbic acid. The enzyme is inactivated by N-bromosuccinimide, $I_2, H_2O_2$. PMSF, and iodoacetate. Judging from the results of their inhibition types, we speculate that tryptophan and serine residues are directly involved in enzyme activity, while tyrosine and methionine residues are indirectly involved in its activity.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.655-662
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• 1992

Pectate lyase produced by recombinant strain containing pectate lyase gene from alkalitolerant Bacillus sp. YA-14 was succesively purified with 257.6 purification folds and a 10.2% yields by the affinity method, eM-cellulose column chromatography followed by gel filtration on Sephadex G-I00 column. The optimal pH and temperature for pectate lyase activity were 10.0 and $60^{\circ}C$, respectively. The enzyme was stable between pH 4.0 and 10.0, and up to $50^{\circ}C$. The molecular weight of this enzyme was estimated to be 43,000 daltons by SDS-PAGE. Amino acid analysis showed that the enzyme contained more polar and basic amino acids, especially serine, glycine and tyrosine, than that of various pectate lyase from other strains. The N-terminal amino acid sequence was Ala-Asp-Leu-Gly-His-Gln-Thr.