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 cell surface component from quiescent BALB/c 3T3 mouse cells that inhibits DNA synthesis and cell division when added to a culture of growing 3T3 cells has been detected. The inhibition of DNA synthesis by this factor was dependent on concentration and time of incubation; a transient exposure of cells to the factor followed by incubation in its absence for 20 hr was sufficient to elicit its inhibitory effect. The active component appears to be protein in nature, as judged by heat inactivation and trypsin sensitivity. Extracts obtained in an identical manner from quiescent 3T3 cells that had been preincubated in situ with uridine diphosphate N-acetyl-D-glucosamine (UDP-GlcNAc) did not inhibit DNA synthesis. The effect was specific for UDP-GlcNAc: incubation with three other nucleotide sugars yielded active component. Incubation of the inactive component from UDP-GlcNAc-treated cells with purified N-acetyl-beta-D-glucosaminidase in vitro restored its inhibitory property. Extracts from growing cells failed to inhibit DNA synthesis. These results suggest that reversible glycosylation with N-acetyl-D-glucosamine residues may serve as a regulatory signal for the conversion of the active factor to its inactive form. We propose that the onset of quiescence of 3T3 cells is due to a casual relationship between depletion of growth factors in the culture medium and the presence of the active regulatory factor on the cell surface that inhibits DNA synthesis; conversion of the regulatory factor to its inactive form under favorable nutritional status may be viewed as a switch that allows DNA synthesis to resume.
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PMID:Control of DNA synthesis in growing BALB/c 3T3 mouse cells by a fibroblast growth regulatory factor. 28 29

Some in-vitro effects of the arthritogenic polysaccharide carrageenin were studied on cells from human synovium. Synovial cells were isolated from intact human knee joints, and cell lines were developed by passaging with trypsin. Carrageenin was ingested by the cells but did not significantly affect cell growth, numbers of lysosomes, intracellular lysosomal enzyme activity (N-acetyl-beta-D-glucosaminidase), or release of lysosomal enzyme from cells. Carrageenin produced a reduction in net hyaluronic acid synthesis. It also induced a striking morphological change in a high proportion of synovial cells, characterised by increased spreading over the culture surface and apparent condensation of the cytoplasm into a pattern of ridges. Nonrheumatoid and rheumatoid synovial cells behaved similarly to one another.
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PMID:Effects of carrageenin on human synovial cells in vitro: morphology, hyaluronic acid production, growth, and the lysosomal system. 38 33

Investigation of pure human pancreatic juice obtained by direct cannulation of the main pancreatic duct of 11 healthy volunteer subjects and 10 chronic alcoholics without detectable pancreatic disease revealed the presence of numerous acid hydrolases in this secretion. The pH optimal and substrate specificities of these enzymes suggest that they are of lysosomal origin. Stimulation of the pancreas by injection of cholecystokinin-pancreozymin (CCK-PZ) (1 Ivy dog unit/kg) resulted in a striking increase in activity of some of these hydrolases (N-acetyl-beta-D-glucosaminidase, arylsulfatase, etc.) similar to that observed for trypsin, amylase, and other pancreatic digestive enzymes. In a second group of hydrolases (beta-D-glucuronidase, leucine naphthylamidase, etc.) the effect of this hormone was greatly reduced or absent, particularly in normal individuals. In chronic alcoholics enzyme activity in response to CCK-PZ injection was greater than in normal subjects. Although this increase achieved statistical significance (P less than 0.05) in the case of beta-D-glucuronidase only, it was observed for all lysosomal hydrolases tested and suggests either increased synthesis or a more facile release of these enzymes from the pancreas of chronic alcoholics than of normal individuals.
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PMID:Lysosomal enzymes in pure pancreatic juice from normal healthy volunteers and chronic alcoholics. 45 5

We have purified epithelial cells from human colonic tumours by velocity sedimentation in an isokinetic density gradient of Ficoll in tissue culture medium. In frozen sections of colonic carcinoma, histochemically demonstrable N-acetyl-beta-D-glucosaminidase (HDAG) was observed primarily in epithelial cells. We used this enzyme as a histochemical marker of epithelial cells. Initial suspensions of cells from colonic tumours suspended with 0-25% trypsin contained an average of 24% of the nucleated cells with HDAG. In the purest fraction obtained from gradient centrifugations, an average of 74% of the nucleated cells contained HDAG. After centrifugation, the quarter of the density gradient which contained the most rapidly sedimenting cells was purified 2-4-fold over that in the initial suspension. Cells in this zone of the gradient also gave rise to colonies in soft agar. Cells from initial suspension resulted in 15-25% as many colonies of 7 or more cells in cultures inoculated with the same number of nucleated cells. For the most part, cells obtained from the other zones of the gradient did not give rise to colonies in soft agar.
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PMID:Partial purification of human colonic carcinoma cells by sedimentation. 87 70

We have measured plasma N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) and neuraminidase (EC 3.2.1.18) activities as markers of glycosidase activity and immunoreactive trypsin (EC 3.4.21.4) levels as a marker of proteolytic potential in the plasma of normal and uraemic subjects. The levels of all of these enzymes are significantly elevated in the plasma of uraemic subjects when compared to normal. We have postulated that the combined attack of glycosidases and proteases on erythropoietin will lead to fragmentation of this glycoprotein hormone with loss of activity. This may be a major contributory cause to the anaemia of chronic renal failure.
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PMID:Increased plasma glycosidase and protease activity in uraemia: possible role in the aetiology of the anaemia of chronic renal failure. 390 90

Secretion of the main lysosomal hydrolase, N-acetyl-beta-D-glucosaminidase of Guinea Pig alveolar macrophages was studied in vitro; without stimulus of phagocytosis or pinocytosis, glycosidase secretion was increased by trypsin. Enzymatic activity secreted under trypsinisation was heterogeneous as compared to the enzymatic activity secreted by control cells: under incubation with Concanavalin A (Con A), glycosidase activity secreted by trypsinised cells decreased by 30%, whereas Concanavalin A did not alter enzymatic activity secreted by control cells.
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PMID:[Effect of trypsin on the cell surface : influence on the lysosomal exocytosis of alveolar macrophages of the guinea pig]. 678 59

The cell surface hydrophobicity, net electric surface charge and cell adhesion of six group B streptococci strains were assessed. Treatment with trypsin reduced cytoadhesion of the six strains (80340, 90356, 85147, 90222, 90186 and 88641) and induced loss of surface negative charge in the other four strains (80340, 85147, 90222 and 90186). The same treatment increased the surface hydrophobicity of three strains (90356, 90222 and 88641). Neuraminidase treatment caused a decrease in the negative surface charge of all the strains resulting in significant increases in both cytoadhesion and surface hydrophobicity of five (80340, 90356, 85147, 90222 and 88641) and four (90356, 85147, 90222 and 88641) strains, respectively. This indicates that sialic acid residues are important anionogenic groups exposed on the streptococcal cell surface. Treatment of buccal epithelial cells with N-acetyl-beta-D-glucosaminidase made them less adherent for most of the strains (80340, 85147, 90222, 90186 and 88641) assayed.
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PMID:Cell surface hydrophobicity and the net electric surface charge of group B streptococci: the role played in the micro-organism-host cell interaction. 747 59

The health of the respiratory tracts of 19 horses was studied for 11 months. The horses were placed into 3 groups (healthy, periodically diseased and continuously diseased) based on the measurements of blood gases, intrapleural pressure and on neutrophil content of tracheal mucus. Lysosomal enzymes (N-acetyl-beta-D-glucosaminidase and beta-glucuronidase) and reflectors of the proteolytic system (plasmin, plasminogen, trypsin inhibitor capacity) were determined. beta-glucuronidase appeared to be a good indicator of the presence of disease of the respiratory system. High beta-glucuronidase values were seen in horses with elevated numbers of neutrophils, elevated arterial alveolar and intrapleural differences as well as in diseased horses during the stabling period. Trypsin inhibitor capacity seemed to be lower in the diseased respiratory system, probably due to the increased consumption of trypsin inhibitors.
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PMID:Beta-glucuronidase and trypsin inhibitor capacity of tracheal lavage fluid as indicators of seasonal airway irritation in the horse. 798 42

The binding of N-acetyl-beta-D-glucosaminidase from rat epididymal fluid to the surface of spermatozoa from the cauda epididymis was measured in the presence of sugars, its phosphorylated derivatives, or after treatment of the cells or the enzyme with agents that alter the integrity of proteins or carbohydrates. The binding was saturable, with a Kd in the nanomolar range, was inhibited with phosphorylated derivates of fructose, and did not depend on Ca2+, showing that it is different from the mannose 6-P-recognizing system existing in other tissues for this and other acid hydrolases. Treatment of the cells with sodium periodate or trypsin inhibited the binding, showing that a glycoprotein of the plasmalemma is involved in the affinity site. Fructose or phosphorylated derivates were not detected in the proteins of the epididymal fluid with HPLC. However, with the method used, the presence of these compounds cannot be ruled out, if among the proteins of the fluid there are only a small number of acid hydrolases containing this sugar.
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PMID:Affinity sites for N-acetyl-beta-D-glucosaminidase on the surface of rat epididymal spermatozoa. 800 7

Intrauterine fluid (IUF) was collected using a tampon from mid-oestrous mares (n = 57) with and without ultrasonically detectable accumulations of free intraluminal fluid. Bacteria were cultured and neutrophils counted from all samples (n = 57). Total protein concentration, trypsin-inhibitor capacity (TIC), and plasmin, beta-glucuronidase (B-Gase) and N-acetyl-beta-D-glucosaminidase (NAGase) activities were determined in 27 IUF samples. The motility of spermatozoa in the presence of IUF, IUF extended with Kenney's medium (1:1) and Kenney's medium alone was analysed in 9 samples using a Hamilton-Thorn motility analyser. Thirty-five mares were inseminated immediately after collection of IUF, and every second day until ovulation. Embryos were recovered nonsurgically 6 days after ovulation. After embryo transfer, fluid accumulations were recorded during oestrus and an endometrial biopsy specimen taken (n = 53). In the beginning of oestrus, fluid accumulations were detected in 39% (22/57) of mares, while on the day when IUF was collected, fluid accumulations were observed in 26% (15/57) of mares. The fluid was anechogenic, and in 80% of the mares located in the uterine body. None of the mares exhibited cytological or bacteriological evidence of acute endometritis. Total protein concentrations, TIC and B-Gase activities in IUF were statistically significantly lower in mares with fluid accumulations (n = 14) than in mares without fluid accumulations (n = 13) (p < 0.01). The addition of undiluted IUF to extended semen significantly reduced total and progressive motilities, path velocities and percentages of rapid spermatozoa (p < 0.05) in vitro. On endometrial biopsy, fibrosis was found to be more prominent (p = 0.025) in mares with fluid accumulations (n = 9) than in mares without (n = 44). It was concluded that anechogenic fluid accumulations during oestrus were associated with compositional changes in IUF. Although IUF had negative effects on spermatozoal motility in vitro, the presence of fluid accumulations at the time of insemination did not affect embryo recovery rates.
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PMID:Intrauterine fluid accumulation in oestrous mares. 912 48


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