Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Neurospora crassa glycogen synthase (UDPglucose:glycogen 4-alpha-glucosyltransferase, EC 2.4.1.11) was purified to electrophoretic homogeneity by a procedure involving ultracentrifugation, DEAE-cellulose column chromatography, (NH4)2SO4 fractionation and 3-aminopropyl-Sepharose column chromatography. The final purified enzyme preparation was almost entirely dependent on glucose-6-P and had a specific activity of 6.9 units per mg of protein. The subunit molecular weight of the glycogen synthase was determined by electrophoresis in sodium dodecyl sulfate-polyacrylamide gel to be 88 000--90 000. The native enzyme was shown to have a molecular weight of 270 000 as determined by sucrose density gradient centrifugation. Thus, the glucose-6-P-dependent form of the N. crassa glycogen synthase can exist as trimer of the subunit. Limited proteolysis with trypsin or chymotrypsin converted the glucose-6-P-dependent form of the enzyme into an apparent glucose-6-P-independent form. The enzyme was shown to catalyze transfer of glucose from UDPglucose to glycogen as well as to its phosphorylase limit dextrin, but not to its beta-amylase limit dextrin. Moreover, glucose, maltose and maltotriose were not active as acceptors.
 ...
PMID:Biosynthesis of glycogen in Neurospora crassa. Purification and properties of the UDPglucose:glycogen 4-alpha-glucosyltransferase. 2 41

Studied was the effect of some physical and chemical factors--heating, acidity, treatment with ultraviolet rays, and enzyme treatment--on the activity of the Brucella abortus 99 cell wall antigen. The activity of the antigen was determined through the microreaction of complement-fixing after Kolmer. It was found that the antigen was most sensitive to acid treatment and treatment with ultraviolet rays, and was more slightly sensitive to the effect of alkaline agents and pronase. Besides, the antigen proved heat-resistant and did not lose its activity after treatment with trypsin and alph- and beta-amylase. The chemical nature of the epitopes (the determinant groups), substantiating the activity of the antigen is briefly discussed.
 ...
PMID:[Effect of physical and chemical factors on the antigenic activity of the cell walls of Brucella abortus 99]. 3 83

When rabbit sperm were pretreated with media of high ionic strength (380 mOsM), which had previously been shown to facilitate removal of sperm-bound seminal plasma components, and subsequently treated with follicular fluid the acrosome reaction was completed rapidly. Treatment of the sperm with follicular fluid alone yielded a greatly decreased rate of acrosome reaction completion, and treatment with the high-ionic strength medium alone caused no visible alteration to the sperm. These results suggest that removal of the sperm-bound seminal plasma components destabilizes the acrosome and prepares it to undergo the acrosome reaction. This destabilization is virtually completed after a 5-minute preincubation of the sperm in high-ionic strength media. Direct comparison of epididymal and ejaculated sperm indicated that epididymal sperm acrosomes were apparently in the same stabilized condition as ejaculated sperm. The effect of the pretreatment by high-ionic strength media could be partially mimicked by pretreatment of sperm with alpha- or beta-amylase or neuraminidase but not by beta-glucuronidase, lipase, pronase, or trypsin. Comparison of the ability of bovine follicular fluid, rabbit follicular fluid, and rabbit serum to induce the rabbit acrosome reaction showed that bovine follicular fluid was 3 to 4 times more effective than rabbit follicular fluid and that rabbit serum was totally ineffective in producing the acrosome reaction. The data support a physiologic role for follicular fluids in the process of fertilization and indicate that removal of sperm-bound seminal plasma components is a prerequisite to efficient induction of the acrosome reaction.
 ...
PMID:Removal of sperm-bound seminal plasma components as a prerequisite to induction of the rabbit acrosome reaction. 124 42

Genetic manipulation of durum wheats by tobacco rab-1 genes influence the trafficking of gluten proteins through the secretory system by up- or down-regulating the transport step from the ER to the Golgi apparatus which may in turn modify functional performance of the grain. Gluten proteins were extracted from two genetically manipulated lines - Svevo B730 1-1 and Ofanto B688 1-2 - and their control lines and were analyzed by two dimensional gel electrophoresis. When the two-dimensional maps were compared by image analysis no significant differences between the GM line with an up-regulated trafficking containing the wild type tobacco rab1 (Svevo B730 1-1) and its control (Svevo control). By contrast, significant differences were found between the GM line with a down-regulated trafficking due to the tobacco rab1 mutant form (Ofanto B688 1-2) and its control (Ofanto control). Of the new protein spots detected in the down-regulated Ofanto B688 1-2 map, only a beta-amylase was identified. The remaining spots were susceptible to chymotripsin action but not to trypsin one, as in the case of the gluten protein. Rheological measurements showed that gluten quality was enhanced in the down-regulated Ofanto B688 1-2 without an increase in the amount of gluten. Proteomics is a useful and powerful tool for investigating protein changes in GMOs and in understanding events in food science and technology.
 ...
PMID:A proteomic approach to study protein variation in GM durum wheat in relation to technological properties of semolina. 1613 35

Of 131 bacterial isolates from seaweed, a culture of Bacillus licheniformis produced a novel protein with antibacterial activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and Listeria monocytogenes. The antibacterial activity was maximal in cultures prepared in Columbia broth containing pieces of synthetic polyurethane sponge and shaken at 210 to 230 rpm. Antibacterial activity was not found in cultures grown statically or with different speeds of rotary shaking. Reduced activity was apparent in supernatants prepared from marine 2216E broth and tryptone soya broth with or without 1% (wt/vol) sodium chloride. The antibacterial compound was sensitive to proteinase K, pronase, and trypsin, but was not affected by Tween-20, -40, -60, or -80, or alpha- or beta-amylase. Activity was not adversely affected by heating up to 40 degrees C or treatment at pH 5 to 14. The bioactive compound was determined to be associated with a protein of 30.7 kDa, which had homology to the YbdN protein of B. licheniformis ATCC 14580.
 ...
PMID:Recovery and characterization of a 30.7-kDa protein from Bacillus licheniformis associated with inhibitory activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and Listeria monocytogenes. 1679 53

The thermal inactivation of a great number of immobilized enzymes shows a biphasic kinetics, which distinctly differs from the first-order inactivation kinetics of the corresponding soluble enzymes. As shown for alpha-amylase, chymotrypsin, and trypsin covalently bound to silica, polystyrene, or polyacrylamide, the dependence of the remaining activities on the heating time can be well described by the sum of two exponential terms. To interpret this mathematical model function, the catalytic properties of immobilized enzymes (number of active sites in silica-bound trypsin, K(M) and E(a) values in silica-bound alpha-amylase and chymotrypsin) at different stages of inactivation and the influence of various factors (coupling conditions, addition of denaturants or stabilizers, etc.) on the thermal inactivation of silica-bound alpha-amylase were studied. Furthermore, conformational alterations in the thermal denaturation of spin-labeled soluble and silica-bound beta-amylase were compared by electron spin resonance (ESR) studies. The results suggest that the biphasic inactivation kinetics reflects two different pathways according to which catalytically identical enzyme molecules are predominantly inactivated.
 ...
PMID:Studies on the thermal inactivation of immobilized enzymes. 1855 55