Physicochemical Properties of Crystalline D-Mannitol Dehydrogenase of Leuconostoc mesenteroides

Abstract

Molecular properties of crystalline NAD: D-mannitol dehydrogenase of Leuconostoc mesenteroides were investigated. The extinction coefficient at 280 nm (E^1%_1cm) and the sedimentation coefficient (s⁰_{20, W}) were determined to be 4.14 and 7.37 s, respectively. The isoelectric point was at pH 3.98 by isoelectric focusing. The molecular weight was estimated to be 137, 000±1, 000 dalton by gel filtration on Sephadex G-200 and Ultrogel AcA 34, and sucrose density gradient centrifugation. The enzyme is consisted of four presumably identical subunits having a molecular weight of 38, 000 dalton. The amino acid composition of the enzyme was determined and characterized the absence of tryptophan in the enzyme molecule.