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)

Two papain inhibitors, I1 and I2, from rat skin extract were purified by affinity chromatography on KSCN-modified papain-agarose gel and by gel filtration on Sephadex G-100. I1 had a molecular weight of 74 000, a pI of 4.6, and it contained 4% of carbohydrates. I1 inhibited papain, ficin, bromelain, rat skin benzoylarginine-2-naphthylamide hydrolase, and to a minor extent, rat skin cathepsin C and bovine trypsin. Bovine chymotrypsin or rat skin cathepsin D were not inhibited and benzoylarginine-2-naphthylamide hydrolase was inhibited only at alkaline pH. An inhibitor corresponding to I1 was present in various rat tissues and also in serum. A similar inhibitor was present in the skin of cat, rabbit, guinea pig, and man. I2 had a molecular weight of 13 400, a pI of 4.9 and it contained no carbohydrates. I2 inhibited all thiol proteases tested, but not trypsin, chymotrypsin, or rat skin cathepsin D. I2 formed an equimolar complex with papain and benzoylarginine-2-naphthylamide hydrolase. I2 was present in rat skin, muscle, lung, and small intestine, but not in kidney, liver, or serum. A similar inhibitor was found in skin extracts of cat, rabbit, guinea pig, and man.
 ...
PMID:Purification and properties of two protease inhibitors from rat skin inhibiting papain and other SH-proteases. 1 95

Using the sucrose haemolysis reaction of Hartmann & Jenkins (1966) as a basic model, the low ionic strength reaction (LISR) of human blood was studied to determine: (1) serum Ig uptake by RBC with saline elution and 125I-IgG uptake, and (2) complement fixation (CF) to RBC with lysis of PNH cells and C3H/C4 antiglobulin haemagglutination (AH) of normal cells. The saline eluates were found to contain IgG and IgM with traces of IgA; their pH optima for the uptake by RBC were 6.0 +/- 0.5, 5.5 +/- 0.5 and c 5.0 respectively. The ratio of bound IgG to IgM was linearly related to the uptake pH. Both C4 AH and lysis were found to be optimum at pH 6.0--7.5, whereas the maximum C3 AH was at pH 6.0 +/- 0.5. The LISR performed at a constant pH (6.1 +/- 0.1) showed that an increasing concentration of neuraminidase (VCN) used in pretreatment of RBC was associated with a decrease in both IgG uptake and CF activity. A maximum VCN effect reduced the Ig uptake to c 20% of normal and abolished almost all the CF activity. An impaired LISR to various degrees was also observed with RBC pretreated with ficin, papain, bromelin, trypsin or protamine, and RBC from two individuals of En(a-) type. Preincubation of serum at LIS with and without RBC resulted in respectively a 'complete' and partial consumption of C in the fluid phase. The latter was not enhanced or inhibited by the addition of VCN-treated RBC for preincubation. A hypothesis is proposed suggesting that in the LSR the Ig uptake by RBC is an electrostatic interaction of the oppositely charged RBC and Ig and the CF to RBC results from C activation by the cell-bound IgG and IgM. In addition, a pH-dependent inactivation of the cell-bound C3 in the LISR is demonstrated.
 ...
PMID:The low ionic strength reaction of human blood: relationship between the binding of serum immunoglobulin and complement of red blood cells and surface charge of the cells. 3 28

Bovine erythrocyte treatment with chymotrypsin, trypsin, pronase, papain, or ficin eliminated or weakened the reactivity of 18 of the 47 blood group factors which were examined. Thirteen of the affected factors were from the B system, and one each was from the C, FV, L, M, and R'S' systems. Variation attributable to pheno-group (allele) or genotype influences was observed in the effects upon six of the factors. Ficin-treated V/V, but not F/V or F/F, cells were rapidly lysed by normal rabbit serum (complement control). Absorptions with pronase-treated V positive cells indicated that essentially all V antigenicity was removed. However, immunizations with pronase-treated V positive cells elicited V antibody production in one of two recipient cows. The numbers of antigens removed by different enzymes did not appear to be closely related to the amount of protein removed.
 ...
PMID:Removal of blood group determinants from bovine erythrocyte membranes. 3. Action of proteolytic enzymes on intact cells. 6 56

A simple method using a cationic dye, toluidine blue (TB), to quantify changes of red cell membrane area has been developed and tested for its validity. After incubating a glucose-depleted red cell suspension with a fixed quantity of TB at 37 degrees C for 10 min, the remaining TB was measured spectrophotometrically at 640 nm. Using this technique, we were able to show differences in TB uptake by populations of young and old red cells. The exact mechanism for TB uptake by the red cells is not clear. Treatment of the cells with bromelin, papain and trypsin reduced the uptake of TB, but neuraminidase and ficin had little or no effect. No inhibition of TB removal by red cells was observed using heparin, D-glucose, glucuronic acid, or N-acetylglucosamine.
 ...
PMID:Evaluation of toluidine blue for measuring erythrocyte membrane loss during in vivo ageing. 8 Oct 69

A high titer antibody was discovered in a healthy young man of blood group A1 R2r. The antibody strongly agglutinated all E positive red blood cells including his own, which had been modified by papain, ficin and bromelin, but only very weakly when modified by trypsin. The antibody was shown to be an IgM antibody. It did not react with unmodified red blood cells.
 ...
PMID:A strong antibody reacting with enzyme modified E positive red blood cells. 11 98

Electrophoretic mobility, membrane sialic acid content and agglutinability by "incomplete" antisera against Rh-o, hr' and k antigens were determined for red blood cells in the course of treatment with trypsin, ficin and neuraminidase. Neuraminidase gradually produces a slight to moderate agglutinability as it reduced surface charge density in proportion to the amount of sialic acid removed. Proteases acted in two distinct steps. The first stage is characterized by the cells rapidly becoming highly agglutinable and by the unmasking of new negative charge as the first half of the sialic acid is removed. In the second stage the cells show a slight gain in agglutinability as surface charge is removed in proportion to sialic acid removal as in the case of neuraminidase. Neuraminidase-treated cells are considerably less agglutinable than cells reduced to the same zeta-potential by protease treatment. The greater efficacy of proteases compared to neuraminidase in making cells agglutinable could be because they not only reduce surface charge density but also increase antigen-antibody bond strength, render antigens more mobile in the membrane to allow clustering in regions of cell to cell antibody bridging and remove glycopeptide chains which may be causing steric hindrance to antigen-antibody binding or to cell-cell contact.
 ...
PMID:Effects of proteases and neuraminidase on RBC surface charge and agglutination. A kinetic study. 16 87

The ascites form of a chemically induced guinea pig hepatoma, line-10, was resistant to killing in vitro by xenogeneic antibody and guinea pig complement. Pretreatment of line-10 cells with certain proteolytic enzymes rendered tham susceptible to the killing action of antibody and guinea pig complement. The effects of enzyme pretreatment were dependent on enzyme concentration, temperature, and could be blocked by addition of competitive or non-competitive inhibitors. The effect of the enzyme treatment could reversed by incubating the treated cells at 37 degrees C (but not at 0 degrees C), in the absence of the enzyme. Effective enzymes included ficin, bromelain, pronase, elastase, papain, trypsin, collagenase, lipases type I and type VI, and the neuraminidase preparation isolated from Clostridium perfringens. The activity of the lipase preparations and the neuraminidase preparation isolated from Clostridium perfringens appeared to be caused by proteolytic enzyme contamination. Enzyme preparations that proved ineffecitve in rendering the line-10 cells sensitive to killing by antibody and guinea pig complement included DNase, RNase, beta-glucuronidase type 6A or type B10, hyaluronidase type V or type VI, and pectinesterase.
 ...
PMID:Lysis of tumor cells by antibody and complement. VI. Enhanced killing of enzyme-pretreated tumor cells. 17 70

A method is described which allows quantitative measurements of bronchomotor function in vitro in all parts of the tracheobronchial tree. With this method it was observed that chymotrypsin, trypsin and ficin elicted contraction in the intrapulmonary airways of rats. The response could be abolished or diminished by phentolamin and atropine. Physostigmine did not potentiate the response. It is concluded that chymotrypsin operates mainly through alpha-adrenoreceptors, whereas trypsin and ficin operate through both a alpha-adrenoreceptors and cholinoceptive receptors.
 ...
PMID:Protease-induced constriction in rats' bronchi. 30 Aug 94

Glia maturation factor from the pig brain can be detected in two molecular forms: the high molecular weight form which is 200 000 dalton in size and the low molecular weight form which is 40 000 dalton in size, as determined by Sephadex gel filtration. The former accounts for 85% of the total biological activity extracted at physiologic pH. The proportion of the low molecular weight form increases following freeze-thawing and ion-exchange chromatography. In addition to the morphological effects, both forms possess mitogenic activity but no esteropeptidase activity. Both forms show similar enzyme susceptibility, being inactivated by papain, ficin and pronase but resistant to subtilisin, thermolysin and trypsin. The high molecular weight form is more resistant to denaturation by low pH, heating and urea than the low molecular weight form. The high molecular weight factor has an isoelectric point of 4.27 whereas the low molecular weight factor has one of 5.04.
 ...
PMID:Multiple molecular forms of glia maturation factor. 46 31

In order to elucidate receptors of proteolytic enzyme-treated red cells which react with Phaseolus coccineus L. lectin, the receptors prepared by affinity chromatography were serologically investigated. P. coccineus lectin had high agglutinin activity for bromelin-, papain- and pronase-treated red cells but that for the cells treated with ficin and trypsin was relatively low. Analyses of chemical composition revealed that sialic acid of the receptors from normal red cells was considerably much as compared with that from the treated cells. On the contrary, the enzyme treatment did not affect particularly carbohydrate composition of the receptors. Disc electrophoresis showed that the patterns of receptors from red cells treated with bromelin or papain were different from those from the other cells. On two-dimensional immunoelectrophoresis, the receptor of trypsin-treated cells gave five precipitation lines against anti-stroma and that of papain-treated cells three lines, but any other receptors showed no line. These findings indicate that there are plural receptors for P. coccineus lectin in red cells treated with each of proteolytic enzymes and that the receptors from respective red cells have electrophoretically and serologically different property.
 ...
PMID:On the receptors of human red cells reacting with Phaseolus coccineus L. lectin. 49 65


1 2 3 4 5 6 7 8 9 10 Next >>