A thermostable polygalacturonate lyase (PL; EC 4.2.2.2) was secreted by Thermomonospora fusca during stationary phase in pectin-mineral salts medium at 52 degrees C. Biosynthesis was induced by addition of pectic substances to cultures growing on glucose or cellulose but not cellobiose; the disaccharide repressed enzyme synthesis and triggered inactivation of enzyme previously secreted. The PL, purified to electrophoretic and serologic homogeneity, had a molecular size of 56 kilodaltons and an isoelectric point at pH 4.16. The amino acid composition closely resembled that of the major extracellular endoglucanases of the actinomycete. The enzyme had six cystine residues but no detectable sulfhydryl groups. It was inactivated by mild reducing agents and activated by oxygenation, indicating the necessity for disulfide bond maintenance. Temperature and pH optima for the PL reaction were 60 degrees C and 10.45, respectively. Calcium was essential for activity but not stability; calcium dependence curves were altered by low concentrations of toxic metals. The Km for pectin increased 30,000-fold as the percent esterification (methoxylation) of that substrate was increased from 0 to 60%. The size of the minimal susceptible site for PL attack on the pectin molecule was calculated as being equivalent to 10 unesterified residues, based on the correlation of Km values at various degrees of esterification with the percentage of cleavable bonds predicted by a random-number-generating computer program.
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http://dx.doi.org/10.1128/jb.169.6.2774-2780.1987 | DOI Listing |
Polymers (Basel)
December 2024
Department of Biotechnology, Institute of Resource Biology and Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
Hemp fibers, recognized for their breathability, specific strength, and ultraviolet resistance, are widely utilized in textile manufacturing and composite materials. Bio-degumming is a promising alternative technology to traditional chemical degumming that can be used to produce hemp fibers due to its eco-friendly nature. However, its lower efficiency has hindered its widespread adoption.
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March 2025
Quantitative Biology Lab, Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT Deemed to Be University), Vellore, Tamil Nadu, India. Electronic address:
Pectate lyases, known for their alkaliphilic nature, are ideal for industrial applications that require specific pH conditions, particularly in industries such as textiles and pulp extraction. These enzymes, primarily from the polysaccharide lyase family 1 (PL1) of different microbial sources, play a vital role in polysaccharide degradation. Given the potent pectinolytic activity of Bacillus pectate lyases, targeting these enzymes is crucial for identifying the most effective candidates.
View Article and Find Full Text PDFPLoS One
December 2024
Liaoning Academy of Agricultural Sciences, Shenyang, China.
Sclerotinia sclerotiorum as a necrotrophic fungus causes the devastating diseases in many important oilseed crops worldwide. The preferred strategy for controlling S. sclerotiorum is to develop resistant varieties, but the molecular mechanisms underlying S.
View Article and Find Full Text PDFFront Microbiol
November 2024
College of Plant Protection, Gansu Agricultural University, Lanzhou, China.
Pectate lyases (PL), as important polysaccharide lyases, play an important role in the infection of host plants by pathogenic. A previous study found that the PL gene was up-regulated in the interaction between 5T-1 and potatoes. In this study, 5T-1 was used as the study object, and its gene function was investigated using bioinformatics analysis, prokaryotic expression, and CRISPR-Cas9 technology.
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January 2025
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.
The plant cell wall is the first barrier against pathogen invasion. Fusarium solani is the primary pathogen responsible for apple replant disease. In this study, we identified an MYB protein, MdMYB54, which interacts with the positive regulator of F.
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