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)

A technique utilizing Pregnant Mare's Serum Gonadotropin and Human Chorionic Gonadotropin treatment of hens (Gallus domesticus), followed by manual ovulation of the excised follicles, was developed to obtain a large number of mature ova. The intact ova were used to test whether acrosin, partially purified from the spermatozoa of the cock (Gallus domesticus), partially purified rabbit testicular acrosin and commercial preparations of several hydrolytic enzymes could dissolve the inner vitelline membrane. Enzymes were applied to pieces of filter paper placed on the ovum. Cock acrosin and endopeptidases such as trypsin, chymotrypsin, collagenase and elastase hydrolyzed the membrane whereas exopeptidases such as leucine aminopeptidase and carboxypeptidase A did not. Phospholipase A, sulfatase, hyaluronidase, beta-glucuronidase and rabbit testicular acrosin also failed to hydrolyze the membrane. Cock acrosin hydrolysis of the ovum surface was inhibited by soybean trypsin inhibitor. The surface of the ovum over the germinal disc region was hydrolyzed more quickly by cock acrosin than the surface over other regions of the ovum. Acrosin from cock sperm caused the release of trichloroacetic acid soluble material absorbing at 280 nm from sonicated preparations of inner vitelline membranes. Hydrolysis was greatest at pH 8.0 and was inhibited by soybean trypsin inhibitor.
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PMID:Hydrolysis of the hen egg vitelline membrane by cock sperm acrosin and other enzymes. 0 Apr 54

Large quantities of the low-molecular-weight natriuretic material (F4), which appears after the salts when fractionated on G-25 Sephadex column, were obtained from the urine of normal man on a normal diet. The natriuretic substance in F4 was (1) untrafiltrable through a membrane with a claimed molecular-weight cut-off of 500 daltons (Amicon UMO5); (2) soluble in more polar organic solvents; (3) totally soluble in 95% acetone when specific activity was doubled; (4) relatively resistant to heating at 100 degrees C for 1 hour at a pH of 10, and to heating at 110 degrees C in 6 N hydrochloric acid for up to 90 hours under anaerobic conditions, and treatment with nitrous acid; it was less resistant to these procedures when extracted into 95% acetone; (5) not destroyed by trypsin, chymotrypsin, pronase, pepsin, leucine aminopeptidase, and subtilysin, nor was it destroyed by pepsin, leucine aminopeptidase, subtilysin, carboxypeptidase A and B, and aminopeptidase M, or by monoamine oxidase, aryl sulphatase, and beta-glucuronidase when extracted into 95% acetone. The natriuretic substance in the 95% acetone-soluble F4 was totally destroyed by incubation with prolidase. The least amount of 95% acetone-soluble F4 required to produce a significant natriuresis in the bioassay rat was that derived from a 7-min sample of urine. The maximal response was obtained from a 30-min sample of urine. Continuous i.v. infusion of the 95% acetone-soluble F4 for 40 min produced a sustained natriuresis, whereas a greater amount injected as a bolus produced an effect which was not sustained beyond 20 min.
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PMID:Further observations on a low-molecular-weight natriuretic substance in the urine of normal man. 4 87

Highly sensitive gelatin substrate films prepared according to a recent variant of the procedure are studied for their susceptibility to the action of various endopeptidases and exopeptidases. Trypsin, papain, elastase, and chymotrypsin are found to hydrolyze the gelatin films most easily, while higher enzyme concentrations are required in case of pepsin, plasmin and collagenase. The exopeptidases, i.e. leucine aminopeptidase, amino acid arylamidase and carboxypeptidases A and B do not cause lysis of gelatin substrate films. The example of a rabbit blastocyst protease involved in implantation is given to demonstrate the application of gelatin substrate film tests for studies of enzymes which have no or little activity against known synthetic substrates (like BANA or GPNA) but hydrolyze gelatin films. Studies of interactions of this blastocyst protease with various inhibitors of known specificity, however, show that the active center of this enzyme nevertheless has striking similarities to trypsin (and also to chymotrypsin). The enzyme is possibly related to elastase. It is emphasized that, besides this, there are a number of different protease type enzymes in rabbit blastocyst and uterine tissues, some of which can be demonstrated only with chromogenic substrates and some only by gelatin methods. Aspects of applicability of the two types of protease tests are briefly discussed.
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PMID:[The specificity and sensitivity of the gelatin base protease substrate film test ]. 4 23

The Rho(D) antigen of red cell membranes was solubilized using ethylene-diamine tetraacetic acid (EDTA) and 2-mercaptoethanol. The solubilized antigen was partially separated from other solubilized membrane components using molecular filtration. The antigen was treated with various enzymes to learn some of the chemical characteristics. It was found that the activity of the antigen, as measured by hemagglutination inhibition, was not affected by bee venom phospholipase A, Clostridium welchii phospholipase C, calf-intestinal alkaline phosphatase, Vibrio cholerae neuraminidase, pig kidney leucine aminopeptidase, bovine pancreatic carboxypeptidase A, and pig pancreatic carboxypeptidase B. However, the proteolytic enzymes, pronase, trypsin, chymotrypsin and papain, did destroy Rho(D) activity as measured by hemagglutination inhibition. These results indicate that protein is an important part of the active determinant of the Rho(D) antigen. The experiments by other investigators have shown that lipid is important to maintain the Rho(D) activity in the intact membrane; lipid probably helps to maintain the structural conformation of the Rho(D) molecule in its natural environment. The solubilized Rho(D) molecules are apparently not dependent on lipid for their Rho(D) activity.
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PMID:Studies on the characterization of the Rho(D) antigen. 10 79

We have perfused isolated rat livers with hypocalcemic (4.4 mg 100 ml) Krebs-Ringer bicarbonate albumin buffer. After 15 min of perfusion, a substance appeared in the perfusate which decreased rat renal adenylate cyclase activation by parathyroid hormone (PTH). The material in the perfusate was purified greater than 50,000-fold by Bio-Gel P-10 chromatography. The purified antagonist decreased the activation of rat renal cortical adenylate cyclase by PTH, glucagon, and epinephrine 75 to 100%. Concentration response curves for each of the hormones indicated a noncompetitive interaction of the inhibitor with the hormone. The inhibition was not species-specific, as the activation of the parathyroid hormone-responsive adenylate cyclase in cat renal cortex was also abolished by the inhibitor from the perfused rat liver. The inhibitor is a peptide, Mr equal to similar to 1000, which is heat-stable, acid-stable, alkai-labile, and is destroyed by trypsin, leucine aminopeptidase, and elastase. It is not destroyed by phosphodiesterase, 5'-nucleotidase, alkaline phosphatase, neuraminidase, RNase, or phospholipase A. The inhibitor is not produced by isolated rat livers perfused with normocalcemic perfusion media. It is unclear whether the peptide is synthesized by the liver or whether it is a breakdown product of a larger peptide or protein in the liver. This is the first reported peptide inhibitor of adenylate cyclase.
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PMID:Isolation of a unique peptide inhibitor of hormone-responsive adenylate cyclase. 16 24

Activities of proteolytic enzymes--cathepsins B and D, trypsin-like proteases, leucine aminopeptidase--as well as of lactate dehydrogenase and its isoenzymes were studied in area of thermic burns of skin and hypodermic tissue, in the zone surrounding the burns area and in intact skin of burned rats. Within a day after burns activities of the enzymes studied were distinctly decreased. The low levels of the activities were within the next three weeks. The activities of the proteolytic enzymes were gradually restored and exceeded the normal level in the tissues situated under crust, in boundary zone and in leukocytes of demarcational zone; the increase in activity appears to affect the subsequent deepening of burn wounds.
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PMID:[Changes in skin enzyme activity in experimental burns]. 20 88

Phosphoenolpyruvate carboxylase from Escherichia coli W was treated with ten proteases, and the effects of the treatments on the enzyme activity and sensitivity to effectors were investigated. Proteases such as trypsin, alpha-chymotrypsin, papain, and subtilisin inactivated the enzyme, whereas elastase, carboxypeptidase Y and leucine aminopeptidase had no effect on the enzyme activity. Elastase and carboxypeptidase Y, however, inactivated the enzyme in the presence of 1 m urea. Subtilisin and alpha-chymotrypsin caused not only inactivation of the enzyme but also a significant desensitization to the effectors. DL-Phospholactate, a potent competitive inhibitor, markedly protected the enzyme from inactivation by subtilisin but did not protect it from desensitization to the effectors. Acetyl-CoA, fructose 1, 6-bisphosphate, and GTP-the allosteric activators--protected the enzyme from subtilisin inactivation, while laurate, the other allosteric activator, accelerated the inactivation. These activators did not protect the enzyme from desensitization to themselves. In contrast, modification with subtilisin in the present of l-aspartate, the allosteric inhibitor, caused an apparent transient activation of the enzyme. The enzyme modified in the presence of L-aspartate retained its sensitivity to L-aspartate, but the sensitivities to the other effectors were reduced to about one-half their initial values. Based on these results, a possible mode of desensitization of the enzyme by subtilisin modification and the possible existence of a multiplicity of conformational states of the enzyme, induced upon binding with the various effectors, are discussed.
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PMID:Phosphoenolpyruvate carboxylase of Escherichia coli. Effect of proteolytic modification on the catalytic and regulatory propties. 38 5

From mouse spinal cord homogenate, we isolated a trophic substance which reverses the post-denervation decrease in tetrodotoxin sensitivity of action potential in organ-cultured extensor digitorum longus muscle of mouse and characterized its physicochemical properties. The trophic substance was separated from macromolecules in homogenate by gel filtration on Biogel P2 column. The partially purified trophic substance was heat-stable, acid-stable and alkaline-labile. The trophic activity was destroyed by lyophilization at neutral pH but not at acidic pH. The trophic activity was abolished by incubation with pronase or leucine aminopeptidase, but not by trypsin, chymotrypsin, thermolysin or carboxypeptidase A. The trophic substance passed through an ultrafiltration membrane UM10 freely. A small part of the trophic activity passed through a UM2 or UM05, and the rest was retained on the membranes. The trophic substance adsorbed on CM-Sephadex at pH 7.2 but passed through DEAE-Sephadex at pH 8.4. These results suggest that the trophic substance regulating tetrodotoxin sensitivity of action potential in mouse skeletal muscle is a peptide with a rather low molecular weight of less than 10,000 and that while the N-terminus of the peptide is free, the C-terminus is probably blocked. This peptide differs from other trophic substances reported previously by other investigators.
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PMID:Partial purification and characterization of neutrophic substance affecting tetrodotoxin sensitivity of organ-cultured mouse muscle. 48 37

In the last 11 years the authors have succeeded in isolating nearly 40 enzyme inhibitors of small molecular size from microbial origins. These inhibitors proved to be not only useful tools in analyses of homeostasis of living organisms but also promising agents for cancer chemotherapy. Leupeptin was originally isolated as an inhibitor against serine or thiol proteases such as trypsin, plasmin, papain and cathepsin B. And soon it was demonstrated that leupeptin suppressed chemical carcinogenesis in rats. Pepstatin has an extremely strong activity to inhibit pepsin and cathepsin D. It also inhibits ascites accumulation caused by neoplastic diseases. Bestatin is a specific inhibitor against aminopeptidase B and leucine aminopeptidase. The enzymes are located on the surface membrane in various kinds of cells including lymphocytes. Bestatin was shown to enhance not only blastogenesis of lymphocytes in vitro but also establishment of delayed-type hypersensitivity in vivo. Combined use of bestatin and other antitumor agents gave promising results in animal experiments. Studies on enzyme inhibitors have provided us a new approach to cancer chemotherapy.
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PMID:Enzyme inhibitors in relation to cancer therapy. 61 3

A population of neonatal mouse keratinocytes (epidermal basal cells) was obtained by gentle, short-term trypsin separation of the epidermal and dermal skin compartments and discontinuous Ficoll gradient purification of the resulting epidermal cells. Over 4--6 wk of culture growth at 32--33 degrees C, the primary cultures formed a complete monolayer that exhibited entire culture stratification and upper cell layer shedding. Transmission and scanning electron microscopy demonstrated that the keratinocyte cultures progressed from one to two cell layers through a series of stratification and specialization phenomena to a six to eight cell layer culture containing structures characteristic of epidermal cells and resembling in vivo epidermal development. The temporal development of primary epidermal cell culture specialization was confirmed by use of two histological techniques which differentially stain the specializing upper cell layers of neonatal mouse skin. No detectable dermal fibroblast co-cultivation was demonstrated by use of the leucine aminopeptidase histochemical technique and routine electron microscope surveillance of the cultures. Incorporation of [3H]thymidine ([3H]Tdr) was greater than 85% into DNA and was inhibited by both 20 micron cytosine arabinoside (Ara-C) and low temperature. Autoradiography and 90% inhibition of [3H]Tdr incorporation by 2 mM hydroxyurea indicated that keratinocyte culture DNA synthesis was scheduled (not a repair phenomenon). The primary keratinocytes showed an oscillating pattern of [3H]Tdr incorporation into DNA over the initial 23--25 days of growth. Autoradiography demonstrated that the cultures contained 10--30% proliferative stem cells from days 2-25 of culture. The reproducibility of both the proliferation and specialization patterns of the described primary epidermal cell culture system indicates that these cultures are a useful tool for investigations of functioning epidermal cell homeostatic control mechanisms.
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PMID:Stratification, specialization, and proliferation of primary keratinocyte cultures. Evidence of a functioning in vitro epidermal cell system. 72 94


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