New enzyme catalysing redox reaction of (keto)cyclitol(s) and cyclo:lactol(s) - is isolated from eye lenses and is useful as analytical reagents in organic synthesis, etc.

摘要

New enzyme protein (I) has the following properties: (1) oxidises cyclitols (II) and derivs., in vitro or in vivo, using NAD derivs. as coenzyme and H-acceptor; (2) oxidises cyclic polyhydroxyalkano-delta-cyclolactols (III) and their derivs. (with pref. for the D-xylopentose configuration) under conditions similar to (1); (3) reduces ketocyclitols (IV) or cyclic polyhydroxyalkano-delta-cyclolactones (V) and their derivs. under similar conditions but with reduced NAD derivs. as coenzyme and H-donor; (4) in these reactions pref. uses NADP(H) or their side-chain derivs; (5) specifically inhibits biocatalytic oxidn. of (II) with (IV); (6) has typical protein properties and reactions (Folin and biuret reactions); (7) m.pt. about 200 deg.C (decomposes with exclusion of air and O2); (8) hydrodynamic equiv. mol.wt. 48000; (9) in native form contains only one peptide unit; (10) electrophoretic migration at pH 7.4 in an acrylamide matrix is anodic; (11) soluble in aq. media contg. 20% EtOH at pH 4-10; (12) constant temp. coefft. of solubility in (NH4)2SO4 soln. between -10 and 50 deg.C; (13 crystallises in birefringent, optically anisotropical crystals by fractional salting out from (NH4)2SO4 soln at 40 (esp. over 62)% saturation; (14) is insol. in CHCl3, xylene and benzene (which destroy its conformational structure and biological activity) in other apolar non-aq. and water-immiscible solvents; (15) contains the aminoacids A,C,D,E,F,G,I,K,L,M,N,P,Q,R,S,T,V,W, and Y among others and include the sequence (where X is unknown aminoacid) NH2-X-X-X-A-Y-E-V-Y-E-I-L-A- K-D-P-S-V-E-V-A-Y-X-X-X-COOH. USE - (I) is useful in a variety of preparative, processing, immunological, diagnostic and analytical procedures, e.g., a starting material for protein and peptide synthesis; as catalyst for prepn. of cyclic keto acids and lactones, ketocycliols or cyclitols; as antigen for antibody prodn. and analysis and for analytical determn. of pyranoses and ketocyclitols. Typical uses of (V) are as acidulants and hardeners; of (IV) as sugar substitutes and starting material in (chiral) organic synthesi