Active-site-directed inhibition of sucrose-phosphate synthase by Cibacron blue F3G-A and 1-deoxynojirimycin
✍ Scribed by Wolf-D. Hatzfeld; Egon Moesinger
- Publisher
- Springer-Verlag
- Year
- 1995
- Tongue
- English
- Weight
- 535 KB
- Volume
- 197
- Category
- Article
- ISSN
- 0032-0935
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✦ Synopsis
Sucrose-phosphate synthase (SPS, E.C. 2.4.1.14) from spinach (Spinacia oleracea L.) was partially purified and the inhibition of the enzyme reaction by 1-deoxynojirimycin and Cibacron blue F3G-A analyzed. Cibacron blue was a high-affinity competitive inhibitor with respect to the substrate UDPglucose (Ki = 80 nM) and a mixed-type inhibitor with respect to fructose-6-phosphate. 1-Deoxynojirimycin was a mixed-type inhibitor of SPS with respect to UDPglucose I-KI~Et) = 5.8 mM] and a uncompetitive inhibitor with respect to fructose 6-phosphate. These results are discussed in relation to the mechanism of the reaction catalysed by SPS and the secondary structure of the enzyme.