Matches in SemOpenAlex for { <https://semopenalex.org/work/W166162973> ?p ?o ?g. }
Showing items 1 to 66 of
66
with 100 items per page.
- W166162973 abstract "An investigation of the substrate specificity of jack bean urease (urea amidohydrolase, EC 3.5.1.5) has revealed that both nitrourea and semicarbazide are substrates for the enzyme. Nitrourea at pH 5.0 has a kcat of 12.4 sec-1 and a Km of 135 mM. The corresponding parameters for semicarbazide at pH 5 and pH 7 are 50.3 sec-1, 29.6 sec-1 and 60 mM, 60 mM (cf. urea, 597 sec-1, 3.28 mM). N-methylurea, methyl carbamate, ethyl carbamate, carbamoyl azide, arginine, acetohydroxamic acid and carbamylcholine are demonstrated not to be substrates within varying degrees of tolerance.Contrary to the report of Jespersen (1975), the final products of the urease-catalysed hydrolysis of urea in both Tris and citrate buffers are carbonic acid and ammonia. Jespersen's measurements may be explained by non-enzymatic reactions of both Tris and citrate with one or other of the products.An extensive investigation of the physical properties of jack bean urease leads to the value 622,000 daltons for its molecular weight. While this value differs markedly from the accepted molecular weight of 483,000 daltons, all measurements in this laboratory are entirely consistent with the higher value. The value for the molecular weight of urease was greatly influenced by nonideality effects, and incomplete allowance for this, together with minimal studies of the partial specific volume and of the diffusion coefficient, led to the earlier, erring, values. The value for v is 0.74 cm3g-1 and for the diffusion coefficient, 3.08 x 10-7 cm2sec-1. The work reported here also points up the paucity of reliable comparative data for proteins of high molecular weight.A large variety of procedures has been used to investigate the active site of jack bean urease. All these studies reinforce the centrality of nickel ion in the mechanism of action of the enzyme. Experiments showed that neither a covalent urease-acetohydroxamic acid complex nor a covalent acyl-enzyme existed. There exists also the clear possibility that an active component of the mechanism of action of this enzyme is a nickel-bound hydroxide ion or water molecule. A generally useful procedure for investigating the presteady state of enzyme-catalysed reactions is partially developed and leads to the conclusion that the first product of the urease-catalysed hydrolysis of urea is the iminol of carbamic acid, rather than carbamic acid itself." @default.
- W166162973 created "2016-06-24" @default.
- W166162973 creator A5069933660 @default.
- W166162973 date "2015-02-03" @default.
- W166162973 modified "2023-09-24" @default.
- W166162973 title "Studies on jack bean urease" @default.
- W166162973 doi "https://doi.org/10.14264/uql.2015.263" @default.
- W166162973 hasPublicationYear "2015" @default.
- W166162973 type Work @default.
- W166162973 sameAs 166162973 @default.
- W166162973 citedByCount "0" @default.
- W166162973 crossrefType "dissertation" @default.
- W166162973 hasAuthorship W166162973A5069933660 @default.
- W166162973 hasConcept C13965031 @default.
- W166162973 hasConcept C155647269 @default.
- W166162973 hasConcept C179104552 @default.
- W166162973 hasConcept C185592680 @default.
- W166162973 hasConcept C2776490341 @default.
- W166162973 hasConcept C2779303437 @default.
- W166162973 hasConcept C2779485144 @default.
- W166162973 hasConcept C2779521917 @default.
- W166162973 hasConcept C2780365088 @default.
- W166162973 hasConcept C2781421780 @default.
- W166162973 hasConcept C55493867 @default.
- W166162973 hasConcept C71240020 @default.
- W166162973 hasConcept C94412978 @default.
- W166162973 hasConceptScore W166162973C13965031 @default.
- W166162973 hasConceptScore W166162973C155647269 @default.
- W166162973 hasConceptScore W166162973C179104552 @default.
- W166162973 hasConceptScore W166162973C185592680 @default.
- W166162973 hasConceptScore W166162973C2776490341 @default.
- W166162973 hasConceptScore W166162973C2779303437 @default.
- W166162973 hasConceptScore W166162973C2779485144 @default.
- W166162973 hasConceptScore W166162973C2779521917 @default.
- W166162973 hasConceptScore W166162973C2780365088 @default.
- W166162973 hasConceptScore W166162973C2781421780 @default.
- W166162973 hasConceptScore W166162973C55493867 @default.
- W166162973 hasConceptScore W166162973C71240020 @default.
- W166162973 hasConceptScore W166162973C94412978 @default.
- W166162973 hasLocation W1661629731 @default.
- W166162973 hasOpenAccess W166162973 @default.
- W166162973 hasPrimaryLocation W1661629731 @default.
- W166162973 hasRelatedWork W1491283823 @default.
- W166162973 hasRelatedWork W1557778156 @default.
- W166162973 hasRelatedWork W1572814777 @default.
- W166162973 hasRelatedWork W1580497766 @default.
- W166162973 hasRelatedWork W1678241784 @default.
- W166162973 hasRelatedWork W1970914383 @default.
- W166162973 hasRelatedWork W1979958672 @default.
- W166162973 hasRelatedWork W1993440167 @default.
- W166162973 hasRelatedWork W1995930972 @default.
- W166162973 hasRelatedWork W2014906912 @default.
- W166162973 hasRelatedWork W2019689199 @default.
- W166162973 hasRelatedWork W2035957162 @default.
- W166162973 hasRelatedWork W2050142403 @default.
- W166162973 hasRelatedWork W2065020160 @default.
- W166162973 hasRelatedWork W206532343 @default.
- W166162973 hasRelatedWork W2087997949 @default.
- W166162973 hasRelatedWork W2554703220 @default.
- W166162973 hasRelatedWork W2784624079 @default.
- W166162973 hasRelatedWork W2913889269 @default.
- W166162973 hasRelatedWork W66067063 @default.
- W166162973 isParatext "false" @default.
- W166162973 isRetracted "false" @default.
- W166162973 magId "166162973" @default.
- W166162973 workType "dissertation" @default.