A STUDY OF ALGINATE LYASES Ⅰ. ISOLATION, PURIFICATION AND KINETICS OF LYASES

The crude enzyme, which was extracted from viscera of Lunella coronata coreensis (Recluz), was salted out and dialysed. Three enzymatic peaks isolated from DEAE-cellulose column chromatography were refered to as lyase Ⅰ, Ⅱ and Ⅲ, respectively. Then these lyases underwent gel-filtration on Sephadex G-25 respectively, and three purer lyases were derived therefrom, the highest purification being 73 fold.
The kinetics of the three lyases was tested respectively. The optimum pH was as follows:lyase Ⅰ was 7.6±0.02 Tris-HCl buffer; lyase Ⅱ was 6.6±0.02 Na₂HPO₄-NaH₂PO₄ buffer; and lyase Ⅲ was 5.6±0.02 HAc-NaAc buffer. In the rang of tested concentration, KCl and Nad were the activator and MnCl₂ was the inhibitor, all for the three lyases; MgCl₂ was the activator for lyases Ⅰ and Ⅱ, but the MgCl₂ of high concentration was the inhibitor for lyase Ⅲ; Pb (OAc)₂ acted differently for three lyases. The Km values of these lyases were 0.2, 0.6 and 0.04 mg/ml in order of precedence.