title: Weak activity of haloalkane dehalogenase LinB with 1,2,3-trichloropropane revealed by X-Ray crystallography and microcalorimetry.
abstract: 1,2,3-Trichloropropane (TCP) is a highly toxic and recalcitrant compound. Haloalkane dehalogenases are bacterial enzymes that catalyze the cleavage of a carbon-halogen bond in a wide range of organic halogenated compounds. Haloalkane dehalogenase LinB from Sphingobium japonicum UT26 has, for a long time, been considered inactive with TCP, since the reaction cannot be easily detected by conventional analytical methods. Here we demonstrate detection of the weak activity (k(cat) = 0.005 s(-1)) of LinB with TCP using X-ray crystallography and microcalorimetry. This observation makes LinB a useful starting material for the development of a new biocatalyst toward TCP by protein engineering. Microcalorimetry is proposed to be a universal method for the detection of weak enzymatic activities. Detection of these activities is becoming increasingly important for engineering novel biocatalysts using the scaffolds of proteins with promiscuous activities.
authors.affiliation: Loschmidt Laboratories, Masaryk University, Kamenice 5/A4, 625 00 Brno, Czech Republic.
authors.forename: Marta
authors.initials: M
authors.lastname: Monincová
authors.forename: Zbynek
authors.initials: Z
authors.lastname: Prokop
authors.forename: Jitka
authors.initials: J
authors.lastname: Vévodová
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nagata
authors.forename: Jirí
authors.initials: J
authors.lastname: Damborsky
mesh_terms: D002151:Calorimetry; D018360:Crystallography, X-Ray; D006867:Hydrolases / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D011407:Propane / Q000031:analogs & derivatives* / Q000378:metabolism; D042301:Sphingomonadaceae / Q000201:enzymology
chemical_list: C009536:1,2,3-trichloropropane; D006867:Hydrolases; C046137:haloalkane dehalogenase; D011407:Propane