Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sciatic nerves from mice were removed and soaked in either PBS (phosphate buffered saline) or PBS plus I% trypsin (Sigma Type III) for various periods of time. Specimens were soaked at either room temperature or 37-degrees C at pH's ranging from 7.5 to 8.0. The epineural and perineural sheaths were split to allow the trypsin to penetrate the nerve. Tissue was prepared for electron microscopy by fixation in cacodylate buffered formaldehyde-glutaraldehyde solutions, post-fixed in OSO4 and embedded in Epon 812 or in glutaraldehyde-urea resin without osmication. After four h incubation at 37-degrees C or eight h at room temperature, the basement membranes of the Schwann cells became fragmented and detached and the myelin intraperiod band lost some density. After 18 h, myelin with swollen intraperiod bands displaying a loss of electron density and split main period bands was noted adjacent to normal myelin. Other areas had been transformed into vesicles indicating that the membranes of these vesicles appeared to have been derived from the detachment of both the intraperiod and main period bands within the myelin. Evidence is presented for the presence of trypsin digestable proteins in both the main period and intraperiod bands of peripheral nervouse system myelin.
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PMID:Electron microscopy of trypsin-digested peripheral nerve myelin. 111 38

In 2 M NaCl, histones H2b, H2a, H3, and H4 form a heterotypic tetrameric complex made up of one chain of each histone. This complex has been analyzed by hydrodynamic techniques. It is indistinguishable from histones in chromatin by its resistance to trypsin, pattern of reactivity with 125I. and ability to form specific crosslinked products after treatment with formaldehyde. It is proposed that this complex is responsible for protecting the small DNA fragments produced by exhausting nuclease digestion of nuclei and that on the average two of these complexes protect the larger 180-200 base pair unit produced by partial treatment of nuclei with nuclease.
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PMID:Histones H2a, H2b, H3, and H4 form a tetrameric complex in solutions of high salt. 116 35

Eight 1-(naphth-1-ylacetyl)-4-substituted thiosemicarbazides and eight 2-(naphth-1-ylmethyl)-5-arylamino-1,3,4-oxadiazoles were synthesized and evaluated for antiinflammatory and antiproteolytic properties. All thiosemicarbazides (100 mg/kg) provided 14-43% protection against carrageenin-induced edema in rats. Cyclization of thiosemicarbazides to oxadiazoles resulted in significant reduction in the antiinflammatory activity. Some of these thiosemicarbazides also possessed low antiinflammatory activity against cotton-pellet-induced granuloma formation and formaldehyde-induced arthritis in rats. Hydrocortisone and oxyphenbutazone, used as reference drugs, exhibited greater antiinflammatory activity. All compounds possessed antiproteolytic activity. The in vitro protection of trypsin-induced hydrolysis of bovine serum albumin, unlike antiinflammatory activity, was greater with oxadiazoles (30-90%) than the precursor thiosemicarbazides (4-50%) at a final concentration of 1 mM.
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PMID:Antiinflammatory and antiproteolytic properties of naphthlthiosemicarbazides and cyclized oxadiazoles. 117 29

Antibodies to multiple epitopes spanning the length of the tau molecule were used to study Alzheimer neurofibrillary tangles (NFT) using immunocytochemical methods and several different methods of fixation and tissue processing, including staining of vibratome sections, hydrated autoclaving of paraffin sections and immunofluorescence of NFT isolated from fresh brain tissue. Smears and sections were pretreated with trypsin and/or phosphatase to further characterize antibody binding. In tissue fixed briefly in periodate-lysine-paraformaldehyde, tau immunoreactivity was detected in astrocytes, but only a few tau epitopes were detected in NFT with this fixation method. In contrast, all tau epitopes were detected in NFT in tissue fixed in formaldehyde for prolonged periods of time. In the hippocampus, the number of NFT detected in the dentate fascia was in proportion to the duration of dementia, as we previously noted. Dentate fascia NFT were intracellular (i-NFT) and were reactive with antibodies recognizing epitopes in both the carboxy- and amino-terminal regions of tau, but not the microtubule-binding domain of tau, suggesting that microtubule-binding domain epitopes are hidden in i-NFT. In contrast, NFT in the subiculum and layer II of the parahippocampal cortex were mostly extracellular (e-NFT), especially in severe cases of long duration. e-NFT were immunoreactive with antibodies to the microtubule-binding domain, but only weakly reactive with antibodies to carboxy- or amino-terminal epitopes, suggesting that e-NFT may contain fragments of tau. In both isolated NFT and NFT in sections, amino-terminal epitopes, including the Alz-50 epitope, were sensitive to trypsin proteolysis, which suggests that the lack of staining of e-NFT by antibodies to the amino-terminal regions of tau is due to proteolysis. Antibodies reactive with amino-terminal epitopes also stained fewer NFT following hydrated autoclaving, while those reacting with the carboxy half of tau stained more NFT after hydrated autoclaving. Thus, although carboxy-terminal regions are not detected in e-NFT, they are probably masked, rather than proteolytically cleaved, since they can be revealed by hydrated autoclaving. Finally, phosphatase treatment of isolated NFT revealed enhanced immunostaining not only with Tau-1, as in previous studies demonstrating abnormal phosphorylation of tau proteins in NFT, but also with an antibody to exon 2, which reveals yet another phosphorylation site in tau of NFT.
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PMID:Immunocytochemistry of neurofibrillary tangles with antibodies to subregions of tau protein: identification of hidden and cleaved tau epitopes and a new phosphorylation site. 128 53

The trypsin-inhibiting activity of human serum is lowered upon addition of formaldehyde or acetaldehyde thereto. Acetaldehyde reacts with alpha-1-proteinase inhibitor (alpha 1-PI) to decrease its trypsin-inhibiting ability. Acetaldehyde has only a slight effect on the tryptic hydrolysis of benzoyl-DL-arginine-p-nitroanilide. It did not decrease the inhibitory activity of the Kunitz inhibitor (Aprotinin) or soybean trypsin inhibitor. Since aldehydes form covalent products with primary amines, primary amides, arginine, tyrosine, and tryptophan in protein, as well as methylene bridges thereby crosslinking functional groups, it is proposed that one or more such interactions affect alpha 1-PI activity. It is further suggested that chronically high levels of acetaldehyde, as a metabolic produce of ethanol, may be a contributory factor to the generation of pancreatitis in alcoholics by possibly lowering the effective alpha 1-PI level which is a natural protective element from proteolysis by trypsin.
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PMID:Acetaldehyde decreases the antitryptic activity of alpha 1-proteinase inhibitor. 131 22

Albumin binding to the endothelial surface apparently initiates its transcytosis via plasmalemmal vesicles and also increases capillary permselectivity. Several albumin-binding proteins, which, we call gp60, gp30, and gp18, have been identified; however, their functional relationship to each other is unclear. In this study, we show that gp30 and gp18 are both variably expressed by cultured rat fibroblasts, smooth muscle cells, and endothelial cells and are present in all tissues examined (heart, lung, skeletal muscle, diaphragm, duodenum, kidney, fat, brain, adrenal, pancreas, and liver). The binding of albumin-gold complexes (A-Au) to gp30 and gp18 was compared with that of native and modified albumins. Monomeric native bovine serum albumin (BSA) interacted much less avidly than A-Au and BSA that was chemically modified by formaldehyde (Fm-BSA) or maleic anhydride (Mal-BSA). Mal-BSA and A-Au have similar affinity constants for gp30 and gp18 (KD approximately 3-7 micrograms/ml (50-100 nM)), which is 1000-fold greater than BSA. These interactions were Ca(2+)-independent but sensitive to pH (< 6.0) and high salt concentrations (> or = 1.0 M). Comparative biochemical characterization provided evidence of conformational changes for Mal-BSA, Fm-BSA, and A-Au. Anti-native BSA serum recognizes BSA much more avidly than modified BSA. Mal-BSA, Fm-BSA, and A-Au are much more sensitive to trypsin digestion than BSA. Cellular processing was also examined. A-Au and Mal-BSA bound at the endothelial cell surface were degraded, whereas BSA was not. Our results indicate that: (i) gp30 and gp18, unlike gp60, are expressed in all tissues tested regardless of the type of endothelia lining the microvasculature and the local mechanism of transendothelial albumin transport; (ii) BSA conformationally modified by either surface adsorption or chemical means not only interacts more avidly with gp30 and gp18 than native albumin but also is preferentially degraded by the cells; (iii) A-Au and native albumin are not equivalent probes for detecting albumin interaction sites; and (iv) gp30 and gp18 exhibit binding behavior resembling scavenger receptors. The possible roles of gp30 and gp18 in albumin binding, transcytosis, endocytosis, and even protein catabolism are discussed.
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PMID:Preferential interaction of albumin-binding proteins, gp30 and gp18, with conformationally modified albumins. Presence in many cells and tissues with a possible role in catabolism. 144

Gelatinous dressings were exposed to gamma-radiation or treated with formaldehyde to improve their resistance to the proteolytic effects of trypsin. After aging of the preparations, both gamma-irradiated and blank samples of gelatinous dressings were etched at a constant rate. Etching rate of the formaldehyde treated dressings decreases during storage.
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PMID:Studies on dressings for dental surgery use. Part 3: Effect of gamma-radiation and of formaldehyde on properties of gelatinous dental dressings. 151 84

Metaphase chromosomes and interphase nuclei of chorionic villus samples (CVS) in five cases were studied after treatment with trypsin and post-fixation in formaldehyde by chromosomal in situ suppression (CISS) hybridization. Our modified protocol enables the use of in situ hybridization techniques on CVS preparations after 42 h of culture. A balanced translocation and trisomy 13 were identified with the aid of CISS hybridization.
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PMID:Chorionic villus metaphase chromosomes and interphase nuclei analysed by chromosomal in situ suppression (CISS) hybridization. 155 11

In this study we report the numbers and metachromatic dye-staining characteristics of mast cells (MCs) in the conjunctiva of normal subjects and patients with seasonal allergic conjunctivitis caused by pollenosis. In addition, we have used a monoclonal antibody to the MC-specific enzyme, tryptase, to enumerate tryptase-positive cells immunohistochemically. Tarsal conjunctival MCs were found to be present in increased numbers in the allergic compared to the nonallergic subjects. Most of the MCs exhibited staining that was formaldehyde resistant, compatible with their identification as connective tissue MCs or basophils. The high positive staining for tryptase confirmed that the metachromatic cells stained with toluidine blue were MCs and not basophils, both in normal and allergic subjects.
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PMID:Mast cell numbers and staining characteristics in the normal and allergic human conjunctiva. 170 23

Mouse alpha-macroglobulin and murinoglobulin were labeled with 125I and utilized for plasma clearance studies performed with mice. Desialylated murinoglobulin was rapidly cleared from the circulation with a half-life of about 5 min. On the other hand, desialylated alpha-macroglobulin showed a biphasic curve: about half was cleared at a rate similar to that of the intact molecule while the remaining half had a shorter half-life of about 20 min which was prolonged by a simultaneous injection of a 200-fold excess of unlabeled asialoorosomucoid. Virtually no cross competition was observed between these asialoglobulins and formaldehyde-treated bovine serum albumin or trypsin-bound alpha-macroglobulin. These results suggest that the intravascular elimination of desialylated alpha-macroglobulin and murinoglobulin is independent of the clearance systems responsible for formaldehyde-modified proteins or proteinase-bound alpha-macroglobulins, and that the structure or spatial arrangement, or both, of oligosaccharide units of alpha-macroglobulin is somewhat different from that of murinoglobulin, resulting in a difference of avidity of interaction with the asialoglycoprotein receptor. The desialylated alpha-macroglobulin and murinoglobulin accumulated principally in the liver.
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PMID:Clearance of desialylated mouse alpha-macroglobulin and murinoglobulin in the mouse. 170 51


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