Purification and properties of an ethylene-forming enzyme from Pseudomonas syringae pv. phaseolicola PK2.
A novel ethylene-forming enzyme that catalyses the formation of ethylene from 2-oxoglutarate was purified from a cell-free extract of Pseudomonas syringae pv. phaseolicola PK2. It was purified about 2800-fold with an overall yield of 53% to a single band of protein after SDS-PAGE. The purified enzyme had a specific activity of 660 nmol ethylene min-1 (mg protein)-1. The molecular mass of the enzyme was approximately 36 kDa by gel filtration and 42 kDa by SDS-PAGE. The isoelectric point and optimum pH were 5.9 and ca. 7.0-7.5, respectively. There was no homology between the N-terminal amino acid sequence of the ethylene-forming enzyme of Ps. syringae pv. phaseolicola PK2 and the sequence of the ethylene-forming enzyme of the fungus Penicillium digitatum IFO 9372. However, the two enzymes have the following properties in common. The presence of 2-oxoglutarate, L-arginine, Fe2+ and oxygen is essential for the enzymic reaction. The enzymes are highly specific for 2-oxoglutarate as substrate and L-arginine as cofactor. EDTA, Tiron, DTNB [5,5'-dithio-bis(2-nitrobenzoate)] and hydrogen peroxide are all effective inhibitors.
Nagahama
K
K
Department of Applied Microbial Technology, Kumamoto Institute of Technology, Japan.
Ogawa
T
T
Fujii
T
T
Tazaki
M
M
Tanase
S
S
Morino
Y
Y
Fukuda
H
H
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005030:Ethylenes / Q000378:metabolism*; D008190:Lyases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D011549:Pseudomonas / Q000201:enzymology*; D013045:Species Specificity
D001426:Bacterial Proteins; D005030:Ethylenes; C036216:ethylene; D008190:Lyases; C034693:ethylene forming enzyme; C072390:ethylene-forming enzyme, Pseudomonas