Tryptophanase from Escherichia coli: catalytic and spectral properties in water-organic solvents.
In water-methanol and water-dimethylformamide (DMF) (1:1 v/v) solutions tryptophanase from E.coli retains its abilities to form a quinonoid complex with quasisubstrates and to catalyze the decomposition of S-o-nitrophenyl-L-cysteine (SOPC). Both the KM and Vmax values decrease in water-organic media. The affinities of tryptophanase for L-alanine, L-tryptophan, oxindolyl-L-alanine and indole in aqueous methanol are decreased, the effect being stronger for the more hydrophobic substances. In a water solution tryptophanase catalizes the reaction of SOPC with indole to form L-tryptophan while in water-organic solvents only decomposition of SOPC is observed.
Institute of Food Substances, Russian Academy of Sciences, Moscow.
N G
NG
Faleev
I S
IS
Dementieva
L N
LN
Zakomirdina
O I
OI
Gogoleva
V M
VM
Belikov
D000409:Alanine / Q000378:metabolism; D002384:Catalysis; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism; D004126:Dimethylformamide / Q000737:chemistry*; D004926:Escherichia coli / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D000432:Methanol / Q000737:chemistry*; D011732:Pyridoxal Phosphate / Q000737:chemistry; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013379:Substrate Specificity; D014364:Tryptophan / Q000378:metabolism; D014368:Tryptophanase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D014867:Water / Q000737:chemistry
D012996:Solutions; D014867:Water; D011732:Pyridoxal Phosphate; C019501:S-o-nitrophenyl-L-cysteine; D004126:Dimethylformamide; D014364:Tryptophan; D014368:Tryptophanase; D003545:Cysteine; D000409:Alanine; D000432:Methanol