In this work, the heterodimeric phospholipase A, HDP-2, from viper venom was investigated for its hydrolytic activity in model myelin membranes as well as for its effects on intermembrane exchange of phospholipids (studied by phosphorescence quenching) and on phospholipid polymorphism (studied by H-NMR spectroscopy) to understand the role of sphingomyelin (SM) in the demyelination of nerve fibers. By using well-validated in vitro approaches, we show that the presence of SM in model myelin membranes leads to a significant inhibition of the hydrolytic activity of HDP-2, decreased intermembrane phospholipid exchange, and reduced phospholipid polymorphism. Using AutoDock software, we show that the NH group of the sphingosine backbone of SM binds to Tyr22(C=O) of HDP-2 via a hydrogen bond which keeps only the polar head of SM inside the HDP-2's active center and positions the sn-2 acyl ester bond away from the active center, thus making it unlikely to hydrolyze the alkyl chains at the sn-2 position. This observation strongly suggests that SM inhibits the catalytic activity of HDP-2 by blocking access to other phospholipids to the active center of the enzyme. Should this observation be verified in further studies, it would offer a tantalizing opportunity for developing effective pharmaceuticals to stop the demyelination of nerve fibers by aberrant PLAs with overt activity - as observed in brain degenerative diseases - by inhibiting SM hydrolysis and/or facilitating SM synthesis in the myelin sheath membrane.
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http://dx.doi.org/10.1007/s00232-024-00327-y | DOI Listing |
J Colloid Interface Sci
December 2024
College of Materials Science and Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, Shandong 266042, China; Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, Shandong 266042, China. Electronic address:
A universal theory for predicting the catalytic activity of hydrolytic nanozymes has yet to be developed. Herein, by investigating the polarization and hydrolysis mechanisms of nanomaterials towards amide bonds, carbocation charge was identified as a key electronic descriptor for predicting catalytic activity in amide hydrolysis. Through machine learning correlation analysis and the Sure Independence Screening and Sparsifying Operator (SISSO) algorithm, this descriptor was interpreted to associate with the d-band center and Lewis acidity on the nanomaterial surface.
View Article and Find Full Text PDFVet Res Commun
January 2025
Soil Science Faculty, Lomonosov Moscow State University, Moscow, 119234, Russia.
Extracellular hydrolytic activity (phospholipase, protease and hemolysin production) was evaluated in 178 strains of potentially pathogenic ascomycetous (Candida parapsilosis, Candida tropicalis) and basidiomycetous (Rhodotorula mucilaginosa) yeasts isolated from the excreta of Mew Gulls. Two bird colonies, one nesting in a natural habitat and the other in an urban habitat at the landfill, were studied simultaneously during their 7-month breeding season. Significant differences in phospholipase and protease production were found between natural and anthropophized strains.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Faculty of Mechanical and Process Engineering, Hochschule Offenburg, 77652 Offenburg, Germany.
Protein hydrolysis under acidic conditions can improve the product quality, nutrient availability, and cost efficiency, particularly when neutral or alkaline enzymes are ineffective. Six fungal aspartic endopeptidases (FAPs) were recombinantly expressed as active enzymes in , with peak activity between 30-50 °C and pH 3.0-4.
View Article and Find Full Text PDFFood Chem
December 2024
College of Food Science and Engineering, Wuhan Polytechnic University, Key Laboratory for Deep Processing of Major Grain and Oil, Ministry of Education, Hubei Key Laboratory for Processing and Transformation of Agricultural Products, Wuhan 430048, China.. Electronic address:
Enzyme-modified butter (EMB) is well-known for its rich flavour, which is primarily defined by the process of enzymatic hydrolysis. This study employed lipidomics and flavouromics to assess the differences between EMBs and to uncover the intrinsic links between volatile organic compounds (VOCs) and lipids. Approximately 273 lipids and 82 VOCs were identified in butter.
View Article and Find Full Text PDFBioorg Chem
December 2024
State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun 130062, China. Electronic address:
Given the ever-evolving landscape of antimicrobial resistance, the emergence of New Delhi metallo-β-lactamase-1 (NDM-1) has introduced a formidable challenge to global public health. In previous research, we identified the Compound Zndm19 as an NDM-1 inhibitor and reported Zndm19 derivatives, which exhibited moderate antibacterial activity when combined with meropenem (MEM). This moderate activity may have been due to the inability of Zndm19 to efficiently penetrate the bacterial outer membrane or its susceptibility to hydrolysis, which prevented it from exerting strong enzyme inhibition in synergy with bacterial cells.
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