A purification procedure for neutral proteases from bacilli is described, in which bacitracin-silica was used as affinity medium. This enabled a one-step purification of the proteases directly from culture supernatant. Since neutral proteases are extremely sensitive towards autodigestion, conditions were chosen such, that autodigestion was largely prevented. Isopropanol appeared to be useful in both eluting the enzymes from the affinity medium, and inhibiting enzymatic activity during this step. The bacitracin-silica medium allowed high flow rates: with columns prepared for use in an FPLC system flow rates up to one column volume per minute were feasible, and still gave satisfactory results. The neutral proteases purified by this method were found to be homogeneous both by SDS-PAGE and analytical gel filtration.
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http://dx.doi.org/10.1016/0165-022x(89)90005-5 | DOI Listing |
Commun Biol
January 2025
Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Prevention, Suzhou Medical College, Soochow University, Suzhou, 215123, China.
Positively charged residues are commonly located near the cytoplasm-membrane interface, which is known as the positive-inside rule in membrane topology. The mechanism underlying the function of these charged residues remains poorly understood. Herein, we studied the function of cytoplasmic residues in corin, a type II transmembrane serine protease in cardiovascular biology.
View Article and Find Full Text PDFPeptide-Ca chelates are innovative calcium supplements. possesses nutritional advantages for preparing calcium-binding peptides (CBPs), although there are limited studies on this subject. Therefore, this paper investigated the optimal condition for preparing CBPs and peptide-calcium chelates (LP-Ca), along with analyzing their microstructure, calcium-binding mechanisms, stability, and calcium transporting efficacy.
View Article and Find Full Text PDFMicroorganisms
November 2024
Yancheng Academy of Fishery Science, Yancheng 224051, China.
is used as a probiotic in animal and human food supplements. Atmospheric and room temperature plasma (ARTP) systems have frequently been used to screen for effective mutant probiotics. In this study, was treated with ARTP, and high-yielding digestive enzyme mutant strains were obtained by measuring the activities of α-amylase, lipase, and neutral protease.
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December 2024
Key Laboratory of Biotechnology and Bioresources Utilization, College of Life Sciences, Dalian Minzu University, Ministry of Education, Dalian 116600, China.
α-amylase can effectively inhibit the activity of digestive enzymes and alter nutrient absorption. The impact of ovum hydrolysates of sea cucumbers on α-amylase activity was investigated in this study. The protein hydrolysates generated using different proteases (pepsin, trypsin, and neutral protease) and molecular weights (less than 3000 and more than 3000) were investigated.
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December 2024
National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
Few studies are concerned with the effect of the conjugat protein on the bioactivities of the abalone gonad polysaccharide (AGP). In this study, a series of treatments, including raw material (female and male) defatting, extraction temperature (25-121 °C), proteolysis, ultrafiltration, and ethanol precipitation, was conducted to investigate the role of the conjugate protein on AGP anticoagulant activity. All AGP extracts significantly prolonged activated partial thromboplastin time (APTT) and thrombin time (TT).
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