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Enzymic Synthesis of Lignin Precursors. Purification and Properties of a Cinnamoyl-CoA: NADPH Reductase from Cell Suspension Cultures of Soybean (Glycine max)
| Content Provider | Scilit |
|---|---|
| Author | Wengenmayer, Herta Ebel, Jurgen Grisebach, Hans |
| Copyright Year | 1976 |
| Description | Journal: Journal of Biological Inorganic Chemistry A cinnamoyl-coenzyme A reductase catalyzing the NADPH-dependent reduction of substituted cinnamoyl-CoA thiol esters to the corresponding cinnamaldehydes was isolated from cell suspension cultures of soybean (Glycine max L. var. Mandarin). A 1660-fold purification of the enzyme was achieved by $(NH_{4})_{2}SO_{4}$ fractionation, chromatography on DEAE-cellulose, hydroxyapatite and Sephadex G-100 and affinity chromatography on 5′-AMP-Sepharose. The apparent molecular weight of the reductase was found to be about 38000 on the basis of the elution volume from a Sephadex G-100 column. Maximum rate of reaction was observed between pH 6.0 and 6.2 in 0.1—0.2 M citrate buffer at 30 °C. The enzyme was markedly inhibited by thiol reagents. The reductase showed a high degree of specificity for cinnamoyl-CoA esters. Feruloyl-CoA was the substrate with the lowest $K_{m}$ value (73 μM) and highest V (230 nkat/mg) followed by 5-hydroxyferuloyl-CoA, sinapoyl-CoA, p-coumaroyl-CoA, caffeoyl-CoA and cinnamoyl-CoA. No reaction took place with acetyl-CoA. The Km value for NADPH varied with the type of substrate. $K_{m}$ values of 28, 120, and 290 pM were found with feruloyl-CoA, sinapoyl-CoA, and p-coumaroyl-CoA, respectively. The rate of reaction observed with NADH was only about 5 % of that found with NADPH. The reaction products CoASH and $NADP^{+}$ inhibited the reaction. The $K_{i}$ values were in the range of 0.5—1 mM and the inhibition was of a noncompetitive (mixed) type. The role of the reductase in the biosynthesis of lignin precursors is discussed. |
| Related Links | https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1976.tb10370.x |
| Ending Page | 536 |
| Page Count | 8 |
| Starting Page | 529 |
| ISSN | 09498257 |
| e-ISSN | 14321327 |
| DOI | 10.1111/j.1432-1033.1976.tb10370.x |
| Journal | Journal of Biological Inorganic Chemistry |
| Issue Number | 2 |
| Volume Number | 65 |
| Language | English |
| Publisher | Wiley-Blackwell |
| Publisher Date | 1976-06-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: Journal of Biological Inorganic Chemistry Biochemical Research |
| Content Type | Text |
| Resource Type | Article |
| Subject | Biochemistry Inorganic Chemistry |
