FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2086732744> ?p ?o ?g. }

• W2086732744 endingPage "3007" @default.
• W2086732744 startingPage "2994" @default.
• W2086732744 abstract "Aspartate ammonia lyases (also referred to as aspartases) catalyze the reversible deamination of l ‐aspartate to yield fumarate and ammonia. In the proposed mechanism for these enzymes, an active site base abstracts a proton from C3 of l ‐aspartate to form an enzyme‐stabilized enediolate intermediate. Ketonization of this intermediate eliminates ammonia and yields the product, fumarate. Although two crystal structures of aspartases have been determined, details of the catalytic mechanism have not yet been elucidated. In the present study, eight active site residues (Thr101, Ser140, Thr141, Asn142, Thr187, His188, Lys324 and Asn326) were mutated in the structurally characterized aspartase (AspB) from Bacillus sp. YM55‐1. On the basis of a model of the complex in which l ‐aspartate was docked manually into the active site of AspB, the residues responsible for binding the amino group of l ‐aspartate were predicted to be Thr101, Asn142 and His188. This postulate is supported by the mutagenesis studies: mutations at these positions resulted in mutant enzymes with reduced activity and significant increases in the K m for l ‐aspartate. Studies of the pH dependence of the kinetic parameters of AspB revealed that a basic group with a p K a of approximately 7 and an acidic group with a p K a of approximately 10 are essential for catalysis. His188 does not play the typical role of active site base or acid because the H188A mutant retained significant activity and displayed an unchanged pH‐rate profile compared to that of wild‐type AspB. Mutation of Ser140 and Thr141 and kinetic analysis of the mutant enzymes revealed that these residues are most likely involved in substrate binding and in stabilizing the enediolate intermediate. Mutagenesis studies corroborate the essential role of Lys324 because all mutations at this position resulted in mutant enzymes that were completely inactive. The substrate‐binding model and kinetic analysis of mutant enzymes suggest that Thr187 and Asn326 assist Lys324 in binding the C1 carboxylate group of the substrate. A catalytic mechanism for AspB is presented that accounts for the observed properties of the mutant enzymes. Several features of the mechanism that are also found in related enzymes are discussed in detail and may help to define a common substrate binding mode for the lyases in the aspartase/fumarase superfamily." @default.
• W2086732744 created "2016-06-24" @default.
• W2086732744 creator A5006246608 @default.
• W2086732744 creator A5015832633 @default.
• W2086732744 creator A5054018838 @default.
• W2086732744 creator A5076345630 @default.
• W2086732744 creator A5076930474 @default.
• W2086732744 date "2009-05-08" @default.
• W2086732744 modified "2023-10-17" @default.
• W2086732744 title "Site‐directed mutagenesis, kinetic and inhibition studies of aspartate ammonia lyase from <i>Bacillus</i> sp. YM55‐1" @default.
• W2086732744 cites W1494574466 @default.
• W2086732744 cites W1499410727 @default.
• W2086732744 cites W1602281251 @default.
• W2086732744 cites W1607363102 @default.
• W2086732744 cites W1625145405 @default.
• W2086732744 cites W1867123511 @default.
• W2086732744 cites W1889898114 @default.
• W2086732744 cites W1927236173 @default.
• W2086732744 cites W1964782964 @default.
• W2086732744 cites W1976145340 @default.
• W2086732744 cites W1985755720 @default.
• W2086732744 cites W1989929509 @default.
• W2086732744 cites W1994072139 @default.
• W2086732744 cites W2000297152 @default.
• W2086732744 cites W2001401830 @default.
• W2086732744 cites W2001900297 @default.
• W2086732744 cites W2013039486 @default.
• W2086732744 cites W2013766722 @default.
• W2086732744 cites W2017954237 @default.
• W2086732744 cites W2031726151 @default.
• W2086732744 cites W2040472442 @default.
• W2086732744 cites W2046707792 @default.
• W2086732744 cites W2058070784 @default.
• W2086732744 cites W2060913542 @default.
• W2086732744 cites W2061624922 @default.
• W2086732744 cites W2064279604 @default.
• W2086732744 cites W2069718785 @default.
• W2086732744 cites W2074499507 @default.
• W2086732744 cites W2078532632 @default.
• W2086732744 cites W2083885647 @default.
• W2086732744 cites W2106244713 @default.
• W2086732744 cites W2156439861 @default.
• W2086732744 cites W4298174337 @default.
• W2086732744 doi "https://doi.org/10.1111/j.1742-4658.2009.07015.x" @default.
• W2086732744 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/19490103" @default.
• W2086732744 hasPublicationYear "2009" @default.
• W2086732744 type Work @default.
• W2086732744 sameAs 2086732744 @default.
• W2086732744 citedByCount "22" @default.
• W2086732744 countsByYear W20867327442012 @default.
• W2086732744 countsByYear W20867327442013 @default.
• W2086732744 countsByYear W20867327442014 @default.
• W2086732744 countsByYear W20867327442018 @default.
• W2086732744 countsByYear W20867327442020 @default.
• W2086732744 countsByYear W20867327442021 @default.
• W2086732744 countsByYear W20867327442022 @default.
• W2086732744 countsByYear W20867327442023 @default.
• W2086732744 crossrefType "journal-article" @default.
• W2086732744 hasAuthorship W2086732744A5006246608 @default.
• W2086732744 hasAuthorship W2086732744A5015832633 @default.
• W2086732744 hasAuthorship W2086732744A5054018838 @default.
• W2086732744 hasAuthorship W2086732744A5076345630 @default.
• W2086732744 hasAuthorship W2086732744A5076930474 @default.
• W2086732744 hasBestOaLocation W20867327441 @default.
• W2086732744 hasConcept C103408237 @default.
• W2086732744 hasConcept C104317684 @default.
• W2086732744 hasConcept C143065580 @default.
• W2086732744 hasConcept C145782189 @default.
• W2086732744 hasConcept C16318435 @default.
• W2086732744 hasConcept C181199279 @default.
• W2086732744 hasConcept C185592680 @default.
• W2086732744 hasConcept C2776382133 @default.
• W2086732744 hasConcept C2777269803 @default.
• W2086732744 hasConcept C2779856020 @default.
• W2086732744 hasConcept C2781208047 @default.
• W2086732744 hasConcept C41183919 @default.
• W2086732744 hasConcept C515207424 @default.
• W2086732744 hasConcept C55493867 @default.
• W2086732744 hasConcept C69034178 @default.
• W2086732744 hasConcept C71240020 @default.
• W2086732744 hasConceptScore W2086732744C103408237 @default.
• W2086732744 hasConceptScore W2086732744C104317684 @default.
• W2086732744 hasConceptScore W2086732744C143065580 @default.
• W2086732744 hasConceptScore W2086732744C145782189 @default.
• W2086732744 hasConceptScore W2086732744C16318435 @default.
• W2086732744 hasConceptScore W2086732744C181199279 @default.
• W2086732744 hasConceptScore W2086732744C185592680 @default.
• W2086732744 hasConceptScore W2086732744C2776382133 @default.
• W2086732744 hasConceptScore W2086732744C2777269803 @default.
• W2086732744 hasConceptScore W2086732744C2779856020 @default.
• W2086732744 hasConceptScore W2086732744C2781208047 @default.
• W2086732744 hasConceptScore W2086732744C41183919 @default.
• W2086732744 hasConceptScore W2086732744C515207424 @default.
• W2086732744 hasConceptScore W2086732744C55493867 @default.
• W2086732744 hasConceptScore W2086732744C69034178 @default.
• W2086732744 hasConceptScore W2086732744C71240020 @default.
• W2086732744 hasIssue "11" @default.
• W2086732744 hasLocation W20867327441 @default.

• next