title: Purification and characterisation of two enzymes related to endogenous formaldehyde in Lentinula edodes.
abstract: In this study, γ-glutamyl transpeptidase (GGT) and l-cysteine sulphoxide lyase (C-S lyase) were purified from the fruiting body of Lentinula edodes in three steps and then characterised. We found that GGT together with C-S lyase caused the generation of endogenous formaldehyde in L. edodes. GGT was composed of a large subunit of 41 kDa and a small subunit of 25 kDa, and C-S lyase was composed of two identical subunits of 46 kDa, as determined by SDS-PAGE. GGT was stable at pH 8.0-10.0 with an optimum pH of 8.8, and was stable at 20-50°C with an optimum activity at 37°C. C-S lyase was stable at pH 8.0-9.0 with an optimum pH of 8.5, and was stable at 20-60°C with an optimum activity at 40°C. The present work supports the study of the mechanism of endogenous formaldehyde in L. edodes.
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Yuan
authors.forename: Xiao-yu
authors.initials: XY
authors.lastname: Lei
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: S A
authors.initials: SA
authors.lastname: Ibrahim
authors.forename: Wen
authors.initials: W
authors.lastname: Huang
mesh_terms: D003545:Cysteine / Q000378:metabolism; D004795:Enzyme Stability; D005557:Formaldehyde / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008190:Lyases / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D020942:Shiitake Mushrooms / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D013379:Substrate Specificity; D005723:gamma-Glutamyltransferase / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D005557:Formaldehyde; D005723:gamma-Glutamyltransferase; D008190:Lyases; D003545:Cysteine