Cucumisin-like protease from the latex of Euphorbia supina.
A protease has been purified from the latex of Euphorbia supina Rafin by two steps of chromatography. The Mr was estimated by SDS-PAGE to be 80 kDa. Its activity was inhibited strongly by diisopropyl fluorophosphate, but not by EDTA, pepstatin, or cysteine protease inhibitors, indicating that the enzyme is a serine protease. The specificity of the protease is broad, but the preferential cleavage sites were C-terminal sites of hydrophobic amino acid residues. The N-terminal sequence of the first fifteen residues was determined and six of the residues match those in cucumisin [EC 3.4.21.25], a protease from the sarcocarp of melon fruit (Cucumis melo L. var. Prince). The results indicate that the E. supina protease is a cucumisin-like serine protease.
Arima
K
K
Department of Chemistry, Faculty of Science, Kagoshima University, Japan.
Uchikoba
T
T
Yonezawa
H
H
Shimada
M
M
Kaneda
M
M
D000595:Amino Acid Sequence; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D019665:Euphorbiaceae / Q000737:chemistry*; D007840:Latex / Q000737:chemistry*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000737:chemistry / Q000302:isolation & purification*
D007840:Latex; D012697:Serine Endopeptidases; C411338:protease B, Euphorbia supina; C041541:cucumisin