87492-68-0Relevant articles and documents
Penicillinase-based amperometric biosensor for penicillin G
Gon?alves, Luís Moreira,Callera, Welder F.A.,Sotomayor, Maria D.P.T.,Bueno, Paulo R.
, p. 131 - 133 (2014)
A biosensor for penicillin G was created by immobilizing penicillinase to a gold electrode by means of a cysteine self-assembled monolayer. The biosensor amperometrically monitored the catalytic hydrolysis of penicillin in a very sensible manner. Furthermore, it was successfully used to measure the Michaelis-Menten enzymatic constant and a low limit of detection of 4.5 nM was obtained.
Mitsumori et al.
, p. 3164 (1977)
Antibiotic resistance: Mono- and dinuclear zinc complexes as metallo-β-lactamase mimics
Tamilselvi,Nethaji, Munirathinam,Mugesh
, p. 7797 - 7806 (2007/10/03)
Biomimetic systems containing one or two zinc(II) ions supported by phenolate ligands were developed as functional mimics of metallo-β- lactamase. These complexes were shown to catalytically hydrolyze β-lactam- substrates, such as oxacillin and penicillin G. The dinuclear zinc complex 1, which has a coordinated water molecule, exhibits high β-lactamase activity, whereas the dinuclear zinc complex 2, which has no water molecules, but labile chloride ligands, shows a much lower activity. The high β-lactamase ac tivity of complex 1 can be ascribed to the presence of a zinc-bound water molecule that is activated by being hydrogen bonded to acetate substituents. The kinetics of the hydrolysis of oxacillin by complex 1 and the effect of pH on the reaction rates are reported in detail. In addition, the kinetic parameters obtained for the synthetic ana logues are compared with those of the natural metallo-β-lactamase from Bacillus cereus (Bell). To understand the role of the second metal ion in hydrolysis, the syntheses and catalytic activities of two mononuclear complexes (3 and 4) that include coordinated water molecules are described. Interestingly, the mononuclear zinc complexes 3 and 4 also exhibit high activity, supporting the assumption that the second zinc ion is not crucial for the β-lactamase activity.
The Mechanisms of Hydrolysis of the γ-Lactam Isatin and its Derivatives
Casey, Lorraine A.,Galt, Ron,Page, Michael I.
, p. 23 - 28 (2007/10/02)
The pH dependences of the rates of hydrolysis of isatin, its N-carboxymethyl derivative and its 5-nitro substituted analogues exhibit a complex behaviour, showing a first- and second-order dependence upon hydroxide ion concentration, as well as a pH-independent pathway.The pH dependence is interpreted in terms of the formation of tetrahedral intermediates in different protonic states which may break down to products via hydroxide ion, hydronium ion and water catalysed pathways.These γ-lactams are as reactive, or more reactive, than benzylpenicillin.
