The conjugates of glucose-6-phosphate dehydrogenase, lactate dehydrogenase, and malate dehydrogenase with progesterone and cortisol, containing 1-40 steroid molecules per enzyme molecule, were obtained by the reactions of N-succinimide esters of the 3-[O-(carboxymethyl)oximes)] of cortisol and progesterone with a protein in a water-DMFA (10%) medium. The catalytic activity and thermostability of dehydrogenases and their steroid conjugates were kinetically studied. The effects of the modification degree on the activity and thermostability of dehydrogenases by their hydrophobization were studied and discussed. Practical recommendations for using the dehydrogenase-steroid conjugates in enzyme immunoassay are given.
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http://dx.doi.org/10.1021/bc00011a003 | DOI Listing |
Int J Mol Sci
January 2025
Departamento de Micro y Nanotecnologías, Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Cto. Exterior S/N, C.U., Coyoacán, Ciudad de México C.P. 04510, Mexico.
Thermus thermophilus HB27 laccase (Tth-Lac) is a thermostable enzyme that contains a β-hairpin (Ala292-Gln307) covering the substrate entrance. We analyzed the role of this β-hairpin in the enzymatic activity of Tth-Lac through three β-hairpin mutants: two variants without the β-hairpin (C1Tth-Lac and C2Tth-Lac) and one with a partially modified β-hairpin (P1Tth-Lac). Enzymatic activity was assayed with different substrates with and without copper.
View Article and Find Full Text PDFSheng Wu Gong Cheng Xue Bao
January 2025
Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Glucose oxidase (GOD) is an oxygen-consuming dehydrogenase that can catalyze the production of gluconic acid hydrogen peroxide from glucose, and its specific mechanism of action makes it promising for applications, while the low catalytic activity and poor thermostability have become the main factors limiting the industrial application of this enzyme. In this study, we used the glucose oxidase GOD reported with the best thermostability as the source sequence for phylogenetic analysis to obtain the GOD with excellent performance. Six genes were screened and successfully synthesized for functional validation.
View Article and Find Full Text PDFNat Chem
January 2025
Institute of Bioengineering, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.
Protein catalysis and allostery require the atomic-level orchestration and motion of residues and ligand, solvent and protein effector molecules. However, the ability to design protein activity through precise protein-solvent cooperative interactions has not yet been demonstrated. Here we report the design of 14 membrane receptors that catalyse G protein nucleotide exchange through diverse engineered allosteric pathways mediated by cooperative networks of intraprotein, protein-ligand and -solvent molecule interactions.
View Article and Find Full Text PDFAntibodies (Basel)
January 2025
MacroGenics Inc., Rockville, MD 20850, USA.
Bispecific antibodies represent a promising class of biologics for cancer treatment. However, their dual specificity and complex structure pose challenges in the engineering process, often resulting in molecules with good functional but poor physicochemical properties. To overcome limitations in the properties of an anti-5T4 x anti-CD3 (α5T4 x αCD3) DART molecule, a phage-display method was developed, which succeeded in simultaneously engineering cross-reactivity to the cynomolgus 5T4 ortholog, improving thermostability and the elevating expression level.
View Article and Find Full Text PDFBiotechnol Prog
January 2025
Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany.
Filamentous fungi are a cornerstone in the biotechnological production of enzymes, proteins, and organic acids. However, challenges in understanding and controlling the relationship between morphology and productivity can limit their application. This study addresses these challenges using Thermothelomyces thermophilus, a promising thermophilic fungus known for the production of thermostable enzymes.
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