The interplay of enzyme active site electrostatics and chemical positioning is important for understanding the origin(s) of enzyme catalysis and the design of novel catalysts. We reconstruct the evolutionary trajectory of TEM-1 β-lactamase to TEM-52 toward extended-spectrum activity to better understand the emergence of antibiotic resistance and to provide insights into the structure-function paradigm and noncovalent interactions involved in catalysis. Utilizing a detailed kinetic analysis and the vibrational Stark effect, we quantify the changes in rates and electric fields in the Michaelis and acyl-enzyme complexes for penicillin G and cefotaxime to ascertain the evolutionary role of electric fields to modulate function. These data are combined with MD simulations to interpret and quantify the substrate-dependent structural changes during evolution. We observe that this evolutionary trajectory utilizes a large preorganized electric field and substrate-dependent chemical positioning to facilitate catalysis. This governs the evolvability, substrate promiscuity, and protein fitness landscape in TEM β-lactamase antibiotic resistance.
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http://dx.doi.org/10.1021/acscentsci.1c00880 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
University of Michigan - Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240, China.
Proton conducting electrochemical cells (PCECs) are efficient and clean intermediate-temperature energy conversion devices. The proton concentration across the PCECs is often nonuniform, and characterizing the distribution of proton concentration can help to locate the position of rate-limiting reactions. However, the determination of the local proton concentration under operating conditions remains challenging.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Chemistry & Chemical Engineering, Henan University of Science and Technology, Luoyang, Henan 471023, People's Republic of China.
The sensitive and selective identification of nitroaromatic explosives and industrially ubiquitous nitrates, which are harmful to the environment, is crucial from the viewpoints of security and environmental remediation. New multifunctional fluorescent porous materials that can sense nitro-explosives and nitrates are under continuous development. To this end, this study synthesizes 3,10,15-/-3,10,16-tribromotrinaphtho[3.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos, 12228-900 São Paulo, Brazil.
Polycyclic aromatic hydrocarbons (PAHs) exhibit intriguing characteristics that position them as promising candidates for advancements in organic semiconductor technologies. Notably, tetracene finds substantial utility in Electronics due to its application in organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs). The strategic introduction of an isoelectronic boron-nitrogen (B,N) pair to replace a carbon-carbon pair in acenes introduces changes in the electronic structure, allowing for the controlled modulation of diradical characteristics.
View Article and Find Full Text PDFInorg Chem
January 2025
School of Chemistry, University of Melbourne, Parkville 3010, Victoria, Australia.
A search for switchable molecules has afforded a family of cobalt complexes featuring derivatives of 2-aminophenol: 4,6-di--butyl aminophenol (HL) and 2-anilino-4,6-di--butyl aminophenol (HL). The heteroleptic cobalt complexes incorporate a Metpa ligand (tpa = tris(2-pyridylmethyl)amine; = 0-3), which involves the methylation of the 6-position of the pyridine ring). Eight members of this family have been synthesized and characterized: [Co(HL)(tpa)](BPh) (), [Co(HL)(Metpa)](BPh) (), [Co(L)(Metpa)](BPh) (), [Co(HL)(Metpa)](BPh) (), [Co(L)(Metpa)](BPh) (), [Co(HL)(tpa)] (BPh)(ClO) (), [Co(L)(tpa)](BPh)(ClO) () and [Co(HL)(Metpa)](BPh) (), where the aminophenol-derived ligands are monoanionic in either the open shell radical iminosemiquinonate (L) or the closed shell protonated aminophenolate (HL).
View Article and Find Full Text PDFFood Sci Biotechnol
January 2025
School of Food Science and Engineering, Henan University of Technology, Lianhua Road 100, Zhengzhou, 450001 Henan People's Republic of China.
Unlabelled: Low-calorie structured lipids are an advanced form of functional lipids made by changing the position of fatty acids attached to the glycerol backbone. The main reason for their production is to get nutraceutical lipids. Different methods are used to synthesize low-calorie structured lipids, like chemical or enzymatic methods.
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