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:3.4.21.1 (chymotrypsin)
10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A fragment, A-II, isolated from a component of a tryptic digest of bovine growth hormone has growth-promoting activity in rats and metabolic activity in humans similar to human growth hormone. The amino acid sequence of this peptide has been reinvestigated and revised. The 38-amino acid peptide was cleaved with cyanogen bromide, chymotrypsin, and trypsin. The amino acid sequences were then established by Edman degradation as well as with overlapping peptides; Homology in the sequence was good between this bovine growth hormone fragment and peptides occurring in ovine growth hormone, human growth hormone, and human chorionic somatomammotropin.
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PMID:Studies on the common active site of growth hormone. Revision of the amino acid sequence of an active fragment of bovine growth hormone. 112 21

Different tissues of the black sea bream Mylio macrocephalus including the liver, gills, intestine, muscle, gonad, swim bladder, spleen, heart and kidney were examined for the presence of prolactin and growth hormone receptors. Membranes were prepared from the tissues and 125I-labeled ovine prolactin and bovine growth hormone were used as ligands. It was found that the liver contained the highest level of specific 125I-labeled ovine prolactin and bovine growth hormone binding, suggesting the existence of hepatic prolactin and growth hormone receptors. The protein nature of the hepatic growth hormone receptor was revealed by the reduction of specific 125I-labeled growth hormone binding after treatment of hepatic membranes with trypsin and chymotrypsin.
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PMID:The sea bream liver contains receptors for growth hormone and prolactin. 141 25

Disordered growth and glucose metabolism secondary to growth hormone deficiency is associated with persistent lymphocytic choriomeningitis virus (LCMV) infection. C3H/St, BALB/WEHI, and SWR/J mice infected at birth with LCMV:ARM carried virus in their blood and organs throughout life but only C3H/St mice developed growth hormone insufficiency. BALB/WEHI and SWR/J infected mice contained normal amounts of growth hormone in their pituitaries and a relatively small proportion of the cells containing growth hormone replicated the virus. In susceptible C3H/St mice, the disease-causing viral strains (LCMV:ARM, E-350, and Pasteur) replicated to higher titers and infected the vast majority of cells producing growth hormone in the anterior lobe of the pituitary. In contrast, LCMV strains Traub and WE replicated in far fewer growth hormone-producing cells and failed to disorder growth hormone synthesis. In another paper (Y. Riviere, R. Ahmed, P. Southern, and M. B. A. Oldstone (1985), Virology 142, 175-182) these findings are used to make reassortants between LCMV:ARM (disease positive) and LCMV:WE (disease nil) and the pathogenic effect is mapped to the small RNA segment of LCMV:ARM. Peptides cleaved by trypsin and chymotrypsin from growth hormone molecules isolated from infected cells or control cells were equivalent when examined by two-dimensional electrophoresis. Further, transfer of antibody to interferon failed to alter the growth hormone insufficiency in these mice, although it corrected LCMV-induced liver disease of BALB mice, suggesting that interferon did not play a dominant role in this disease. The selective tropism of LCMV:ARM for cells containing growth hormone over cells that contain prolactin was observed in both infected animals and in cultured GH-3 cells.
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PMID:Perturbation of differentiated functions during viral infection in vivo. I. Relationship of lymphocytic choriomeningitis virus and host strains to growth hormone deficiency. 241 1

In primary cultures of rat preadipocytes (PA) isolated from epididymal or perirenal depots, rat serum is more effective than other animal sera (fetal calf, newborn calf, human, horse, rabbit, cat, sheep, goat, dog, pig) in promoting adipogenic conversion, biochemical differentiation, and mitogenesis. Only mouse serum is comparable to rat serum. This activity is attributable to a specific growth factor (preadipocyte stimulating factor, PSF). An assay for PSF in rat serum was devised using PA from perirenal fat of 3-month-old Fischer 344 rats grown first to confluence in FCS for 8 days and then for the next 3 days in test serum, followed by measurement of triglyceride (TG) and glycerol-3-phosphate dehydrogenase (GPDH). Rat serum induces dose-dependent rapid cell division, which coincides with accumulation of TG and increase of GPDH; for routine quantitation, TG is assayed. The biochemical characteristics of PSF in serum are as follows: stable at 4 degrees C for up to 1 year; inactivated at 100 degrees C (80% loss, 30 min) but stable at 56 degrees C for 1 hr; stable at pH 2-12; non-dialyzable; completely resistant to pepsin, trypsin, and chymotrypsin but destroyed by pronase and subtilisn; stable to DTT and periodate; and m.w. between 68 kDa (Sephacryl-300) and 58 kDa (Sephacryl-300 in 5 M urea). PSF activity is greater in serum from Wistar than from Fischer 344 rats, while activity of serum from Zucker obese (fa/fa) rats is at least as great as that from Wistar rats and, like serum of rats made obese by feeding a high-fat, high-carbohydrate diet, is not suppressed. PSF activity is not due to insulin, insulin-like growth factor-1 (IGF-1), growth hormone, glucocorticoids, or combinations of these hormones. PSF activity was not seen with a number of growth factors including colony-stimulating factor (CSF-1), GM-CSF, interleukins 1, 2, and 3, neuroleukin, tumor necrosis factor, and others. PSF is distinct from the low molecular weight (4-8 kDa) differentiation factor present in rat serum, FCS, and human serum that promotes the adipogenic conversion and cellular differentiation of 3T3-L1, 3T3-F442A, and Ob17 cells. PSF appears to be a new differentiation factor for rat preadipocytes, has properties suggestive of a highly glycosylated protein, and may be highly species specific.
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PMID:Preadipocyte stimulating factor in rat serum: evidence for a discrete 63 kDa protein that promotes cell differentiation of rat preadipocytes in primary cultures. 268 98

Parathyroid hormone (PTH) -degrading activity was studied using osteoblast-like UMR-106 cells. PTH-degrading activity was assessed by the amount of PTH fragments produced in the medium after exposure of intact human PTH-(1-84) to UMR-106 cells. PTH immunoreactivity recovered in trichloroacetic acid-soluble products of the medium and in fractions eluted from reverse-phase high-performance liquid chromatography (HPLC) was measured by radioimmunoassay using an antibody specific for the mid-region and C-terminus of PTH. In this study, intact UMR-106 cells but not extracellular enzymes cleaved human PTH(1-84) into fragments which were released into the medium (in a time- and temperature-dependent fashion). HPLC analysis of the PTH fragments depicted three immunoreactive peaks (peaks 1, 2 and 3) besides intact PTH, indicating a limited PTH-hydrolyzing activity of the cells. Furthermore, a 1000-fold molar excess of either hPTH-(3-34) or [Nle8,Nle18,Tyr34]hPTH-(3-34)amide inhibited PTH-degrading activity by 63% and 80% of control, respectively, whereas neither calcitonin, vasopressin nor growth hormone suppressed it. Additionally, HPLC analysis of the samples treated with [Nle8,Nle18,Tyr34]hPTH-(3-34)amide showed a reduction of the three peaks, suggesting an involvement of PTH receptor in the production of PTH fragments. This PTH-degrading activity was strongly inhibited by phenylmethylsulfonyl fluoride and chymostatin, but not by soybean trypsin inhibitor, elastatinal or inhibitors of cysteine, aspartic or metalloproteinases, indicating that it is due to a seryl chymotrypsin-like endopeptidase. Chymotrypsin-like activity seems to be solely responsible for PTH-degrading activity in intact UMR-106 cells, since all three PTH fragments were predominantly suppressed in the presence of chymostatin. Further analysis of chymotrypsin-digested products of hPTH-(1-84) eluted from HPLC exhibited five fragments detected by ultraviolet absorbance at 210 nm, three of which were measurable by PTH radioimmunoassay, each corresponding to the three PTH fragments produced by UMR-106 cells. To explore the cleavage sites of PTH further, amino acid analysis of chymotrypsin-cleaved products was performed. The results strongly support the view that the chymotrypsin-like enzyme in UMR-106 cells cleaved the hormone between residues 23-24 and 34-35, to produce, at least, hPTH-(24-84) and -(35-84). Our present study indicates that a chymotrypsin-like endopeptidase is solely responsible for limited hydrolysis of PTH by intact UMR-106 cells.
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PMID:Parathyroid hormone degradation by chymotrypsin-like endopeptidase in the clonal osteogenic UMR-106 cell. 291 1

Evaluation of devices, drugs, and drug delivery systems have been investigated by both in vitro and in vivo procedures. Ceramic drug delivery systems can be used to evaluate chemicals and biologicals by both in vitro and in vivo procedures. The system can also reduce handling of the animals and facilitate long-term evaluations before conducting clinical trials. To date, ceramic systems have been used to deliver aldosterone, androstanedione, beta-lactoglobulin, bovine serum albumin, chymotrypsin, danazol, difluoromeythylornithine, dihydrotestosterone, estradiol, gamma globulin, gonadotrophic releasing hormone, gossypol, growth hormone, insulin, methylene blue, pepsin, progesterone, and testosterone. The data obtained suggest that ceramic delivery systems can be used in the near future to treat diseases requiring long-term chronic drug therapy as well as disorders caused by deficiency of certain hormones.
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PMID:Ceramic systems for long-term delivery of chemicals and biologicals. 323 59

Transfection of genes into tissue culture cell lines has demonstrated that relatively short DNA sequences can allow expression of immunoglobulin, insulin and chymotrypsin genes in their appropriate cell types. A definitive test of cell-specific gene expression, however, requires testing genes in every possible cell type, an experiment performed easily by introducing the gene in question into the germ line of an animal. Transfer of intact genes into mice has demonstrated that a mouse immunoglobulin kappa gene is expressed specifically in B lymphocytes, a rat elastase I gene is expressed specifically in pancreas and a chicken transferrin gene is expressed preferentially in liver. Mouse metallothionein-growth hormone fusion genes introduced into mice are preferentially expressed in the liver, consistent with the expression of endogenous metallothionein genes, but initial experiments with beta-globin genes have not revealed proper regulation. To identify the DNA elements required for pancreas-specific expression of the rat elastase I gene, we joined the 5'-flanking region of this gene to the human growth hormone (hGH) structural gene and introduced the fusion gene into mice. Here we demonstrate that a fusion gene containing only 213 base pairs (bp) of elastase I gene sequence directs expression of hGH in pancreatic acinar cells.
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PMID:Specific expression of an elastase-human growth hormone fusion gene in pancreatic acinar cells of transgenic mice. 384 51

The time required to induce two inducible hepatic enzymes, ornithine decarboxylase (ODC) and tyrosine aminotransferase (TAT), by growth hormone and dexamethasone, respectively, increases with age. Specific activity at the peak of induction is the same for all ages. On the other hand, for basal TAT the specific activity per unit of TAT antigen was found to decrease considerably with age. The half-life of ODC was determined after cycloheximide administration. The apparent half-life at the peak of ODC induction increases from 15 minutes in 3-4-month-old mice to 30 minutes in 24-month-old animals. Loss of efficiency in the protein degradation system is implicated in this phenomenon as no apparent differences could be observed in the susceptibility of ODC and TAT from young or old mice to chymotrypsin. ODC and TAT are activated by temperatures of up to 37 degrees C and 50 degrees C, respectively. ODC is inactivated at 50 degrees C while TAT is inactivated at 76 degrees C. "Young" ODC and TAT are more readily activated or inactivated by heating than the "old" enzymes.
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PMID:Age-related changes in inducible mouse liver enzymes: ornithine decarboxylase and tyrosine aminotransferase. 610 55

Membranes were prepared from tissues of the carp Ctenopharynogodon idellus including liver, kidney, intestine, adipose tissue, ovary, gill, heart, muscle and spleen. The carp liver and intestine membranes bound 125I-labeled bovine growth hormone and the binding could be displaced by cold bovine growth hormone. No changes in the ability to bind 125I-labeled bovine growth hormone occurred after treatment of the carp liver membrane with DNase, RNase, alpha-amylase and beta-glucosidase, suggesting that neither nucleic acids nor carbohydrates played an important part in the hepatic binding of growth hormone. Treatment of carp liver membranes with either chymotrypsin or trypsin produced a decrease in the growth hormone binding activity, indicating that the growth hormone receptor on carp liver membrane is a protein. Treatment of carp liver membranes with p-chloromercuribenzoate brought about a reduction in 125I-bGH binding. The inhibition could be reversed by dithioerythritol, suggesting the involvement of essential sulfhydryl group in bGH binding.
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PMID:Presence of growth hormone receptors in carp liver and intestine. 849 May 77

Ovoinhibitor is a serine protease-inhibiting protein that was originally purified from egg whites. It is secreted by the oviduct under the control of estrogen and progesterone and it specifically inhibits serine proteinases such as trypsin and chymotrypsin. During recent attempts to raise monoclonal antibodies (Mabs) against chicken bursa of Fabricius proteins, one Mab was produced that specifically recognized chicken ovoinhibitor. This was the first demonstration of ovoinhibitor in an avian immune organ. We presently report on the expression of an ovoinhibitor-like molecule by the pituitary of the chicken as revealed by immunocytochemistry and RT-PCR. Immunofluorescent dual staining experiments using the mouse anti-ovoinhibitor Mab in conjunction with polyclonal antibodies against various hypophysial hormones revealed partial co-localization of an ovoinhibitor-like molecule with growth hormone (GH), luteinizing hormone (LH), and pro-opiomelanocortin (POMC), in a subset of the respective hormone producing cells. By contrast, no co-localization with prolactin (PRL) could be reliably demonstrated. RT-PCR of hypophysial mRNA using ovoinhibitor gene-specific primers yielded an amplicon that was 20% shorter than predicted on the basis of the published ovoinhibitor sequence. Sequencing revealed that of the represented exons only the central portion was expressed in the pituitary and that both 5' and 3' ends of each exon had been truncated. While expression of ovalbumin-like serine protease inhibitors (serpins) has been previously reported in the rat pituitary, to our knowledge, this is the first report of a Kazal-type serine protease inhibitor in the vertebrate neuroendocrine system.
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PMID:The chicken pituitary expresses an ovoinhibitor-like protein in subpopulations of some, but not all, hormone-producing cell types. 1465 38


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