Purification and Characterization of New Alkaline L-methioninase from Aspergillus ustus AUMC 1051 Grown under Solid-State Fermentation Conditions. | ||||
| Egyptian Journal of Botany | ||||
| Article 15, Volume 56, Issue 3, September 2016, Page 785-798 PDF (351.68 K) | ||||
| Document Type: Regular issue (Original Article) | ||||
| DOI: 10.21608/ejbo.2016.3775 | ||||
 View on SCiNiTO | ||||
| Abstract | ||||
| ALKALINE L-methioninase (E.C.4.4.1.11) from Aspergillus ……. ustus AUMC 1051 was obtained in a good yield amounting to 1321 Uml-1 (99.56 Ug-1 bran) under solid state fermentation (SSF) of wheat bran. The enzyme was purified 15.83-fold with 62.63% yield after three steps of purification involved ammonium sulfate precipitation, Sephadex G-100 gel filtration and DEAE-cellulose ion exchange chromatography. The purified enzyme had a molecular mass of 46 kDa under denaturating conditions and an isoelectric point of 6. Maximal activity was recorded at pH 8.5 and 35oC. Good stability of the purified enzyme was detected over wide pH values ranging from 8 to 10 and temperature up to 50oC. The enzyme retained its full activity after 6 days of storage at 4oC. Four weeks was found the T1/2 of its activity. Vmax and Km, of the purified enzyme were found to be 820 Uml-1 and 1.6 mM, respectively. Alkaline L-methioninase activity was stimulated by Na+ and Co+2 and strongly inhibited by Hydroxylamine, iodoacetate, Hg+2 and Cu+2. The enzyme was proved to be glycoprotein containing -SH group in its catalytic site. | ||||
| Keywords | ||||
| solid-state fermentation; Alkaline L-methioninase; Purification; Characterization; Aspergillus ustus | ||||
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