TY - JOUR
T1 - NADH-dependent dehydroascorbate reductase in the rabbit lens
AU - Akatsuka, Ichiko
AU - Bando, Masayasu
AU - Obazawa, Hajime
AU - Oka, Mikako
AU - Takehana, Makoto
AU - Kobayashi, Shizuko
PY - 2001/4/1
Y1 - 2001/4/1
N2 - The present investigation demonstrates the existence of NADH-dependent dehydroascorbate (DHA) reductase activity in the soluble fraction of the rabbit lens. This DHA reductase was specific for NADH, and its apparent Km values for DHA and NADH were 5.7 mM and 4.0 μM, respectively. In a gel filtration of the lens soluble fraction on a Sephadex G-75 superfine column, the NADH-dependent DHA reductase activity was eluted at the oligomeric βL1-crystallin fraction, which may also contain λ-crystallin (a rabbit-specific crystallin). Furthermore, about 80% of protein fractions separated from the βL1-crystallin fraction by DEAE-cellulose ion-exchange column chromatography exhibited DHA reductase activity. In the SDS-PAGE analysis of the protein fractions with DHA reductase activity, 32-33, 27 and 25 kDa protein subunit s were commonly identified. These results suggest that oligomers of β-crystallin and/or λ-crystallin subunits may be associated with the DHA reductase activity. The present paper also discusses that the function of the reductase may be to enhance the antiphotoxidation capacity of the lens.
AB - The present investigation demonstrates the existence of NADH-dependent dehydroascorbate (DHA) reductase activity in the soluble fraction of the rabbit lens. This DHA reductase was specific for NADH, and its apparent Km values for DHA and NADH were 5.7 mM and 4.0 μM, respectively. In a gel filtration of the lens soluble fraction on a Sephadex G-75 superfine column, the NADH-dependent DHA reductase activity was eluted at the oligomeric βL1-crystallin fraction, which may also contain λ-crystallin (a rabbit-specific crystallin). Furthermore, about 80% of protein fractions separated from the βL1-crystallin fraction by DEAE-cellulose ion-exchange column chromatography exhibited DHA reductase activity. In the SDS-PAGE analysis of the protein fractions with DHA reductase activity, 32-33, 27 and 25 kDa protein subunit s were commonly identified. These results suggest that oligomers of β-crystallin and/or λ-crystallin subunits may be associated with the DHA reductase activity. The present paper also discusses that the function of the reductase may be to enhance the antiphotoxidation capacity of the lens.
KW - Dehydroascorbate reductase
KW - Enzyme/Crystallin, antiphotoxidation
KW - NADH-specific
KW - Rabbit lens
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M3 - Article
C2 - 11592299
AN - SCOPUS:0035321959
SN - 0385-0005
VL - 26
SP - 25
EP - 32
JO - Tokai Journal of Experimental and Clinical Medicine
JF - Tokai Journal of Experimental and Clinical Medicine
IS - 1
ER -