2003
Catalytic mechanism of the haloalkane dehalogenase LinB from Sphingomonas paucimobilis UT26
PROKOP, Zbyněk, Marta MONINCOVÁ, Radka CHALOUPKOVÁ, Martin KLVAŇA, Yuji NAGATA et. al.Základní údaje
Originální název
Catalytic mechanism of the haloalkane dehalogenase LinB from Sphingomonas paucimobilis UT26
Autoři
PROKOP, Zbyněk (203 Česká republika, garant), Marta MONINCOVÁ (203 Česká republika), Radka CHALOUPKOVÁ (203 Česká republika), Martin KLVAŇA (203 Česká republika), Yuji NAGATA (392 Japonsko), Dick B. JANSSEN (528 Nizozemské království) a Jiří DAMBORSKÝ (203 Česká republika)
Vydání
Journal of Biological Chemistry, 2003, 0021-9258
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10600 1.6 Biological sciences
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 6.482
Kód RIV
RIV/00216224:14310/03:00009155
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000186452300008
Klíčová slova anglicky
ENZYME; KINETICS; MECHANISM; LINB; HALOALKANE DEHALOGENASE
Štítky
Změněno: 19. 3. 2010 11:05, prof. Mgr. Jiří Damborský, Dr.
Anotace
V originále
Haloalkane dehalogenases are bacterial enzymes capable of carbon-halogen bond cleavage in halogenated compounds. To obtain insight in the mechanism of the haloalkane dehalogenase from Sphingomonas paucimobilis UT26 (LinB), we studied the steady-state and pre-steady-state kinetics of the conversion of the substrates 1-chlorohexane, chlorocyclohexane and bromocyclohexane. The results lead to a proposal of a minimal kinetic mechanism consisting of three main steps: (i) substrate binding, (ii) cleavage of the carbon-halogen bond with simultaneous formation of an alkyl-enzyme intermediate and (iii) hydrolysis of the alkyl-enzyme intermediate. Release of both products, halide and alcohol, is a fast process that was not included in reaction mechanism as a distinct step. Comparison of the kinetic mechanism of LinB with that of haloalkane dehalogenase DhlA from Xantobacter autotrophicus GJ10 and the haloalkane dehalogenase DhaA from Rhodococcus rhodochrous NCIMB 13064 shows that the overall mechanisms are similar. The main difference is in the rate-limiting step, which is hydrolysis of the alkyl-enzyme intermediate in LinB, halide release in DhlA, and liberation of an alcohol in DhaA. The occurrence of different rate-limiting steps for three enzymes that belong to the same protein family indicates that extrapolation of this important catalytic property from one enzyme to another can be misleading even for evolutionary closely related proteins. The differences in the rate-limiting step were related to: (i) a number and size of the entrance tunnels, (ii) protein flexibility and (iii) composition of the halide-stabilizing active site residues based on comparison of protein structures.
Návaznosti
LN00A016, projekt VaV |
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