Grimontia hollisae collagenase (Ghcol) exhibits high collagen-degrading activity. To explore its catalytic mechanism, its substrate (Gly-Pro-Hyp-Gly-Pro-Hyp, GPOGPO)-complexed crystal structure was determined at 2.0 Å resolution. A water molecule was observed near the active-site zinc ion. Since this water was not observed in the product (GPO)-complexed Ghcol, it was hypothesized that the GPOGPO-complexed Ghcol structure reflects a Michaelis complex, providing a structural basis for understanding the catalytic mechanism. Analyses of the active-site geometry and site-directed mutagenesis of the active-site tyrosine residues revealed that Glu493 and Tyr564 were essential for catalysis, suggesting that Glu493 functions as an acid and base catalyst while Tyr564 stabilizes the tetrahedral complex in the transition state. These results shed light on the catalytic mechanism of bacterial collagenase.
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http://dx.doi.org/10.1002/1873-3468.14732 | DOI Listing |
Crit Rev Anal Chem
January 2025
Department of Chemistry, University of Delhi, New Delhi, India.
Heavy metal pollution is a major environmental and health problem due to the toxicity and persistence of metals such as lead, mercury, cadmium, and arsenic in water, soil, and air. Advances in sensor technology have significantly improved the detection and quantification of heavy metals, providing real-time monitoring and mitigation tools. This review explores recent developments in heavy metal detection, focusing on innovative uses of immobilized chromogenic reagents, nanomaterials, perovskites, and nanozymes.
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January 2025
Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
1,4-Azaborine-based arenes are promising electroluminescent emitters with thermally activated delayed fluorescence (TADF), offering narrow emission spectra and high quantum yields due to a multi-resonance (MR) effect. However, their practical application is constrained by their limited operational stability. This study investigates the degradation mechanism of MR-TADF molecules.
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January 2025
Key Laboratory of Chem-Biosensing of Anhui Province, Key Laboratory of Functional Molecular Solids of Anhui Province, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, Anhui, China. Electronic address:
Adsorption and biodegradation are two important means to remove the pollutants from the environment, but how to combine them and improve the catalytic performance and stability of free enzyme are facing great challenges. Herein, lipase from Candida rugosa (CRL) was immobilized into bimetallic ZnCo-MOF by biomineralization, which not only significantly improved the catalytic activity and stability of CRL but also endowed it with excellent reusability. Furthermore, CRL@ZnCo-MOF established a synergetic system of combined adsorption and enzymatic degradation for the sustainable removal of dibutyl phthalate (DBP) in actual water environment.
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December 2024
Department of Gastrointestinal Surgery, Yantaishan Hospital, Yantai, Shandong Province, China. Electronic address:
Histocompatibility minor 13 (HM13) is a signal sequence stubbed intramembrane cleavage catalytic protein. Increasing evidence supports the association among HM13 expression, tumor-infiltrating immune cells (TIICs), and cancer. However, its role on formation and progression of colorectal cancer (CRC) has not been explored.
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January 2025
Department of Medical, Surgical and Health Sciences, University of Trieste, 34149 Trieste, Italy.
Head and neck squamous cell carcinomas (HNSCCs) represent a heterogeneous group of malignancies with multifactorial aetiologies. High-risk human papillomavirus (hrHPV) infections, particularly HPV16, and the dysregulation of telomerase activity, specifically through its catalytic subunit, telomerase reverse transcriptase (TERT) are among the key contributors to HNSCC development and progression. HPV promotes oncogenesis via the E6 and E7 oncoproteins, which inactivate tumour suppressors TP53 and RB1, leading to unchecked cellular proliferation.
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