Purification and properties of soluble and bound gamma-glutamyltransferases from radish cotyledon.
Soluble and cell wall bound gamma-glutamyltransferases (GGTs) were purified from radish (Raphanus sativus L.) cotyledons. Soluble GGTs (GGT I and II) had the same M(r) of 63,000, and were composed of a heavy subunit (M(r), 42,000) and a light one (M(r), 21,000). The properties of GGT I and II were similar. Bound GGTs (GGT A and B) were purified to homogeneity from the pellet after the extraction of soluble GGTs. GGT A and B were monomeric proteins with an M(r) of 61,000. The properties of GGT A and B were similar. Thus, bound GGTs were distinguished from soluble GGTs. The optimal pHs of soluble and bound GGTs were about 7.5. Both soluble and bound GGTs utilized glutathione, gamma-L-glutamyl-p-nitroanilide, oxidized glutathione and the conjugate of glutathione with monobromobimane as substrates, and were inhibited by acivicin, but soluble GGTs were also distinguished from bound GGTs with regard to these properties.
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan.
Yoshihiro
Y
Nakano
Satoshi
S
Okawa
Takayoshi
T
Yamauchi
Yukio
Y
Koizumi
Jiro
J
Sekiya
D002853:Chromatography, Liquid; D018548:Cotyledon / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D031224:Raphanus / Q000201:enzymology* / Q000378:metabolism; D012995:Solubility; D013379:Substrate Specificity; D005723:gamma-Glutamyltransferase / Q000302:isolation & purification* / Q000378:metabolism*
D005723:gamma-Glutamyltransferase