1. Metallic nanoparticles bioassay for Enterobacter cloacae P99 β-lactamase activity and inhibitor screening
Rongrong Liu, Weiling Teo, Bengang Xing*. Analyst, 2010, 135, 1031–1036
In a silver nanoparticle based enzyme inhibition assay, a yellow solution revealed the potent enzyme inhibition and an orange-red color demonstrated the weak inhibition and aggregation of AgNPs occurred at this stage. As shown in Fig. 4A, the observed yellow color in ATM indicated the strongest Bla inhibition. The slight orange color in TZB revealed the weaker inhibition than ATMand the orange color in SUL exhibited a weaker enzyme inhibition than those in ATM and TZB but stronger than that in CA. Similarly, in a gold nanoparticle based enzyme inhibition assay, a red color implied a signiﬁcant effectiveness in the enzyme inhibition against aggregation whereas a blue color indicated the least inhibition and allowed the enzymatic reaction to proceed, resulting in the aggregation of AuNPs (Fig. 4B). The different colors associated with the different extents of aggregation provided the following enzyme inhibition trend: ATM > TZB > SUL > CA as shown in Fig. 5A and 5B.
2. The enzymes ofβ-lactam biosynthesis
Refaat B. Hamed,* J. Ruben Gomez-Castellanos, Luc Henry, Christopher J. Schoﬁeld*. Nat. Prod. Rep., 2013, 30,21–107
With the exception of aztreonam and the carbapenems, clinically used β-lactams are produced either by isolation of fermented compounds (e.g. clavulanic acid) or by synthetic or enzymatic modification of fermented compounds (e.g. many penicillins and all such cephalosporins). For this reason, β-lactam biosynthesis has been a focal point for the application of new methodologies in molecular biology with a view to optimising production procedures. Presently, there is interest in optimising sustainable routes to pharmaceuticals. It would seem likely that if there is resurgence in interest in BLAs research,manipulation of their biosynthesis pathwaysmight be an important tool for the eﬃcient and sustainable production of new antibiotics.
3. Zn2+ catalysed hydrolysis of β-lactams: experimental and theoretical studies on the inﬂuence of the b-lactam structurey
Natalia Dıaz, Tomas L. Sordo, Dimas Sua ´rez,* Rosa Me ´ndez and Javier Martın-Villacorta*. New. J. Chem. , 2004, 28, 15–25
We employed the algorithm developed for AutoDock, which uses a Monte Carlo simulated annealing technique for the conﬁgurational exploration of enzyme–ligand complexes with a rapid energy evaluation using grid-based molecular interaction potentials built from van der Waals and electrostatic contributions. Aztreonam was docked at the static binding site of the B. cereus zinc-b-lactamase. During the docking process, the internal bonds of the aztreonam sidechains were allowed to rotate.