Studies of a novel cysteine sulfoxide lyase from Petiveria alliacea: the first heteromeric alliinase.
A novel alliinase (EC 4.4.1.4) was detected and purified from the roots of the Amazonian medicinal plant Petiveria alliacea. The isolated enzyme is a heteropentameric glycoprotein composed of two alpha-subunits (68.1 kD each), one beta-subunit (56.0 kD), one gamma-subunit (24.8 kD), and one delta-subunit (13.9 kD). The two alpha-subunits are connected by a disulfide bridge, and both alpha- and beta-subunits are glycosylated. The enzyme has an isoelectric point of 4.78 and pH and temperature optima of 8.0 and approximately 52 degrees C, respectively. Its activation energy with its natural substrate S-benzyl-l-cysteine sulfoxide is 64.6 kJ mol(-1). Kinetic studies showed that both K(m) and V(max) vary as a function of substrate structure, with the most preferred substrates being the naturally occurring P. alliacea compounds S-benzyl-l-cysteine sulfoxide and S-2-hydroxyethyl-l-cysteine sulfoxide. The alliinase reacts with these substrates to produce S-benzyl phenylmethanethiosulfinate and S-(2-hydroxyethyl) 2-hydroxyethanethiosulfinate, respectively.
Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, USA. musah@albany.edu
Rabi A
RA
Musah
Quan
Q
He
Roman
R
Kubec
Abhijit
A
Jadhav
D013437:Carbon-Sulfur Lyases / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000031:analogs & derivatives / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D007526:Isoelectric Point; D015394:Molecular Structure; D008970:Molecular Weight; D029602:Phytolaccaceae / Q000737:chemistry / Q000201:enzymology*; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D013379:Substrate Specificity; D013441:Sulfinic Acids / Q000737:chemistry
D010940:Plant Proteins; C529747:S-benzyl phenylmethanethiosulfinate; C445736:S-benzyl-cysteine sulfoxide; D013441:Sulfinic Acids; D013437:Carbon-Sulfur Lyases; C019971:cysteine lyase; C019243:alliin lyase; D003545:Cysteine