Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pseudorabies virus hemagglutinin was readily adsorbed on mouse erythrocytes at 4, 22, or 37 degrees C, but not on cattle erythrocytes. The adsorbed hemagglutinin could not be eluted from the cells by resuspending in phosphate-buffered saline (PBS), by incubating at 37 or 50 degrees C, or by incubating in the presence of neuraminidase. The receptor on mouse erythrocytes for the hemagglutinin was inactivated by trypsin, but not by neuraminidase, sodium deoxycholate (DOC), potassium periodate (KIO4), dithiothreitol (DTT), 2-mercaptoethanol (2-ME) and formalin. The hemagglutinin was inactivated by trypsin, alpha-amylase, pepsin, DOC, KIO4, and ethylendiamine-tetraacetic acid (EDTA), but not by papain, beta-glucosidase, phospholipase C, neuraminidase, DTT, 2-ME, Tween-80, ethylether, chloroform, trichloro-trifluoroethane, beta-propiolactone and formalin, suggesting that the hemagglutinin active component involved glycoproteins. The hemagglutinin was stable at 37 degrees C for lower temperatures but not at 60 degrees C or higher. The hemagglutinin activity was resistant to ultraviolet irradiation, while the infectivity was very susceptible. The hemagglutinin and the infectivity were readily sedimented by ultracentrifugation at 48,000 x g for 3 hr. In rate zonal centrifugation of the preparation on a sucrose density gradient, the hemagglutination (HA) activity showed a sharp peak at 1.22 g/ml coinciding with the peak of infectivity. The HA activity in the peak fraction seemed to be structually associated with virus particles. After fractionation of the virus by Nonidet P-40, the HA activity was found only in the fraction of the envelope material, indicating that the hemagglutinin is situated in the viral envelop.
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PMID:Physicochemical properties of pseudorabies virus hemagglutinin. 166 85

A new method that uses nonradioactive active site-directed enzyme inactivators and high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESIMS/MS) to identify labeled peptides in a proteolytic digest is described. This method relies upon the fragmentation of labeled peptides in a predictable and reproducible manner in the collision cell of a tandem mass spectrometer. The exoglycanase from Cellulomonas fimi, endoglucanase C from Clostridium thermocellum, and the beta-glucosidase from Agrobacterium faecalis were labeled using 2-deoxy-2-halo-beta-glycosides, digested with pepsin, and subjected to HPLC-ESIMS/MS analysis, scanning in the neutral loss mode. Under these conditions only peptides that lose the (known) mass of the label are detected. Preliminary identification of candidate peptides can be achieved from the mass measured, in combination with the known sequence of the protein. Peptide identity can be confirmed through subsequent sequencing, either via further tandem MS experiments or via the Edman degradation. In all cases the peptides identified in this manner were consistent with those identified by the standard radioactive method. This mass spectrometric method represents a rapid, nonradioisotopic solution to the problem of identifying a modified peptide in a complex mixture. The technique is also sensitive, requiring only picomole amounts of protein.
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PMID:Identification of derivatized peptides without radiolabels: tandem mass spectrometric localization of the tagged active-site nucleophiles of two cellulases and a beta-glucosidase. 773 52

Porcine reproductive and respiratory syndrome virus hemagglutinin (HAin) was readily adsorbed on mouse erythrocytes at 4, 22, or 37 degrees C, but not on goose erythrocytes. The adsorbed HAin could not be eluted from the cells by resuspending in phosphate buffered saline, by incubating at 37 or 50 degrees C, or by incubating in the presence of neuraminidase. The hemagglutinating activity was not dependent on the pH and NaCl molarity tested. The receptor of mouse erythrocytes for the HAin was relatively stable to trypsin, neuraminidase, sodium deoxycholate (DOC), potassium periodate (KIO4), dithiothreitol (DTT), 2-mercaptoethanol (2-ME) and formalin treatments. The HAin was inactivated by 2-ME and was gradually inactivated by pepsin, formalin and DTT, but not by beta-glucosidase, trypsin, alpha-amylase, papain, phospholipase C, neuraminidase, KIO4, and ethylendiamine tetraacetic acid (EDTA) treatments. The HAin was stable at 37 degrees C or lower temperatures, but not at 56 degrees C or higher. The HAin was relatively resistant to ultraviolet irradiation and sonication. In the equilibrium centrifugation of the HAin preparation on a CsCl density gradient, the HAin activity showed a sharp peak at 1.17 g/cm2. In the SDS-PAGE analysis, the structural polypeptide of HAin in the peak fraction seems to be the nucleocapsid (N) polypeptide with molecular weight of 15 kDa.
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PMID:Characterization of porcine reproductive and respiratory syndrome virus hemagglutinin. 915 37

Potential feed enzyme additives for ruminants were tested in vitro for their stability to ruminal microbial and gastrointestinal proteolysis. Four commercial preparations from Trichoderma longibrachiatum (A, B, C, and D) and one from an undisclosed source (E) were incubated up to 6 h with ruminal fluid taken from four lactating dairy cows before or 2 h after feeding. The stability of preparation B was also tested in the presence of pepsin at pH 3 and pancreatin at pH 7. Cellulase (EC 3.2.1.4), cellulose 1,4-beta-cellobiosidase (EC 3.2.1.91), beta-glucanase (EC 3.2.1.6), xylanase (EC 3.2.1.8), beta-glucosidase (EC 3.2.1.21), and beta-xylosidase (EC 3.2.1.37) activities were monitored throughout the incubations. Polysaccharidase activities of all enzyme preparations were remarkably stable in ruminal fluid taken after feeding. Ruminal fluid obtained before feeding inactivated the polysaccharidases in preparations B and D to a greater extent than ruminal fluid obtained after feeding. Cellulase and cellulose 1,4-beta-cellobiosidase activities were the least stable, declining (P < 0.05) by 35 and 60% for preparations B and D, respectively. Xylanase activity of preparation D decreased (P < 0.05) by up to 30% after 6 h of incubation, whereas beta-glucanase activity was not affected. The ability to degrade exogenous enzymes also differed among cows (P < 0.05). Pepsin and acid (pH 3.0) did not affect polysaccharidases in preparation B but decreased glycosidase activities by 10 to 15% (P < 0.05) after 1 h of incubation. Pancreatin, at the maximum concentration used, inactivated cellulase, cellulose 1,4-beta-cellobiosidase, and xylanase activities at a rate of 0.55, 1, and 0.45%/min, respectively. beta-Glucosidase and beta-xylosidase activities decreased by 1 and 0.75%/min, respectively. Partial proteolysis of cellulase, cellulose 1,4-beta-cellobiosidase, and xylanase by pancreatin produced a transient increase in activity. This twofold increase for cellulase and fourfold increase for cellulose 1,4-beta-cellobiosidase was directly proportional to pancreatin concentration. These results suggest that the enzyme feed additives tested were stable in the rumen of animals after feeding. Exogenous enzymes are likely to be more susceptible to the host gastrointestinal proteases in the abomasum and intestines than to ruminal proteases. However, exogenous polysaccharidases may survive for a considerable period of time in the small intestine and they probably maintain activity against target substrates in this environment.
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PMID:Resistance of feed enzymes to proteolytic inactivation by rumen microorganisms and gastrointestinal proteases. 1142 1

There was an ionic interaction between acidic polysaccharides (APS) and proteins at the pH range in which APS were negatively charged and proteins were positively charged, and in enzymes the interaction was detected as a change in the enzyme activity. At pH 4.7, acid phosphatase (pI, 5.4), alpha-glucosidase (pI, 5.7), and beta-glucosidase (pI, 7.3) were inhibited by APS to various extents. On the other hand, alpha-glucosidase and alkaline phosphatase (pI, 4.5) were not inhibited by APS at pH 6.8 and 9.8, respectively, most of these two enzymes being negatively charged at the respective pHs. Sulfated polysaccharides combined with hemoglobin (pI, 6.8 to approximately 7.0) by an ionic bond at pH 2 to make hemoglobin unsusceptible to proteolysis by pepsin, but polyuronides which were not charged at this pH did not affect hydrolysis of hemoglobin.
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PMID:Interaction between acidic polysaccharides and proteins. 1295 27

A molecular display technology that uses the displayed proteins on cell surfaces has many applications in microbiology and molecular biology. Here, we describe the resistance of displayed proteins to proteases using simulated gastric fluid (SGF), which included pepsin at pH 2. The displayed beta-glucosidase resisted pepsin digestion compared with secreted, free beta-glucosidase. In SDS-PAGE and Western blotting analysis, the secreted beta-glucosidase was immediately digested within 1 min following SGF treatment, although the displayed beta-glucosidase was stable for more than 60 min following SGF treatment. In addition, the residual activity of secreted beta-glucosidase was completely destroyed after 10 min SGF treatment. However, displayed beta-glucosidase retained 14% of its residual activity following the same treatment. These results clearly show that cell surface display technology using enzymes can reveal the protease resistance of a protein of interest under various conditions.
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PMID:Evaluation of cell surface-displayed protein stability against simulated gastric fluid. 1943 Sep 13

Beta-glucosidase (BGL1) is widely used in animal feed industries. However, degradation caused by digestive enzymes in the intestine hampers its application. Improving the resistance of feed enzymes against proteases is crucial in livestock farming. To improve the resistance of beta-glucosidase against pepsin and trypsin, a rational molecular design based on the inhibition of bound-state formation and secondary design was developed. The strategy includes: (1) prediction of the interaction surface of the pepsin-BGL1 complex structure, (2) prediction of key amino acids affecting the formation of the complex, (3) optimization of pepsin-resistant mutants by structural evaluation, (4) secondary molecular design based on pepsin-resistant mutants, and optimization of pepsin and trypsin-resistant mutants. Two BGL1 protein mutants (BGL1Q627C and BGL1Q627C/R543H/R646W) were constructed, and then mutated and wild-type BGL1s were expressed in Pichia pastoris. The half-life of BGL1Q627C and BGL1Q627C/R543H/R646W were 1.36 and 1.51 times that of the wild type upon pepsin exposure, respectively. For trypsin resistance, the half-life were 0.93 and 1.53 times that of the wild type, respectively. Compare to those of the wild type, most of the basic enzymatic properties of both mutants were not significantly changed except for increased Michaelis constants. The rational design method can be used as a guide for modifying other feed enzymes.
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PMID:Rational molecular design for improving digestive enzyme resistance of beta-glucosidase from Trichoderma viride based on inhibition of bound state formation. 3187 95