BMB Reports
- Volume 32 Issue 6
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- Pages.605-609
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- 1999
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- 1976-670X(eISSN)
An L-Type Thioltransferase from Arabidopsis thaliana Leaves
- Kim, Tae-Soo (Division of Life Sciences. Kangwon National University) ;
- Cho, Young-Wook (Division of Life Sciences. Kangwon National University) ;
- Kim, Joon-Chul (Division of Life Sciences. Kangwon National University) ;
- Jin, Chang-Duck (Division of Life Sciences. Kangwon National University) ;
- Han, Tae-Jin (Department of Biology, Haliym University) ;
- Park, Soo-Sun (The National Academy of Sciences) ;
- Lim, Chang-Jin (Division of Life Sciences. Kangwon National University)
- Published : 1999.11.30
Abstract
Thioltransferase, also called glutaredoxin, is a general GSH-disulfide reductase of importance for redox regulation. Previously, the protein thioltransferase, now called S-type thioltransferase, was purified and characterized from Arabidopsis thaliana seed. In the present study, a second thioltransferase, called L-type thioltransferase, was purified to homogeneity from Arabidopsis thaliana leaves. The purification procedures included DEAE-cellulose ion-exchange chromatography, Sephadex G-50 gel filtration, and glutathione-agarose affinity chromatography. The purified enzyme was confirmed to show a unique band on SDS-PAGE and its molecular weight was estimated to be 26.6 kDa, which appeared to be atypical compared with those of most other thioltransferase. It could utilize 2-hydroxyethyl disulfide, S-sulfocysteine, and insulin as substrates, and also contained dehydroascorbate reductase activity. Its optimum pH was 8.5 and its activity was greatly activated by L-cysteine. When it was kept for 30 min, it appeared to be very stable up to