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

---

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

Peptides inhibitory to the 70-kDa endopeptidase (PepO) from the cytoplasm of Lactococcus lactis ssp. lactis MG1363 were isolated from the supernatant (pH 4.6) of chymosin, tryptic and alpha-chymotryptic hydrolysates of beta-casein (beta-CN) by reversed-phase HPLC and identified by sequencing and mass spectrometry. Chymosin released beta-CN f193-209, kinetic constant (Ki) of which for inhibition of PepO was 60 microM. This peptide also inhibited (Ki = 1700 microM) the 95-kDa aminopeptidase (PepN) from L. lactis ssp. lactis MG 1363. Trypsin released two PepO-inhibitory peptides: one, beta-CN f69-97, was not degradable by PepO (Ki = 4.7 microM), while the other, beta-CN f141-163, was degradable by PepO but competitively inhibited hydrolysis of methionine enkephalin by PepO. A peptide, beta-CN f69-84, which inhibited PepO with a Ki of 8.1 microM, was isolated from the alpha-chymotryptic hydrolysate. Peptides released from beta-CN by trypsin or chymotrypsin had very little inhibitory activity against PepN. PepO degraded beta-CN f193-209 very slowly compared with the hydrolysis of methionine enkephalin. All four inhibitory peptides (beta-CN f193-209, f69-97, f69-84, f141-163) were readily degraded by thermolysin.
...
PMID:Peptides inhibitory to endopeptidase and aminopeptidase from Lactococcus lactis ssp. lactis MG1363, released from bovine beta-casein by chymosin, trypsin or chymotrypsin. 863 36

Digestion of blood within the mosquito midgut is mediated primarily by a series of proteases, and several previous studies have described protease activity within homogenates of the midgut of the malaria vector Anopheles stephensi. We have expanded on these previous data by resolving protease isoforms from the midgut as well as the hemolymph of adult An. stephensi mosquitoes via gel electrophoresis and zymography. Using this procedure, we have been able to identify multiple isozymes of trypsin, chymotrypsin, and aminopeptidase. We were able to detect an increase in the intensity of some of these protease bands plus the appearance of new bands 24 hr after mosquitoes had taken a blood meal. Furthermore, we detected 2 endogenous trypsin isozymes within the hemolymph. There was no upregulation of these hemolymph isozymes after a blood meal, thus suggesting that they may not be involved in digestion of the blood meal by the mosquito.
...
PMID:Identification of electrophoretically separated proteases from midgut and hemolymph of adult Anopheles stephensi mosquitoes. 957 12

Three proteolytic enzymes, trypsin, chymotrypsin, and aminopeptidase-N (APN), were purified from laboratory-reared western spruce budworm, Choristoneura occidentalis [Freeman], larvae. Budworm trypsin exhibited a high degree of substrate specificity, was inactivated by DFP and TLCK, and was inhibited by trypsin inhibitors. The western spruce budworm chymotrypsin hydrolyzed SAAPFpNA and SAAPLpNA, but not SFpNA, SGGFpNA, SGGLpNA or BTpNA. The chymotrypsin was inactivated by DFP, and was inhibited by chymostatin and the chymotrypsin inhibitor, POT-1. Purified budworm chymotrypsin exhibited little BTEE esterolytic activity and was insensitive to inhibition with TPCK. The N-terminal sequence of budworm trypsin, chymotrypsin, and APN were obtained. Similar levels of trypsin and APN gut activities were found in laboratory-reared and field-collected larvae. However, in comparison to laboratory-reared insects, considerably less chymotrypsin activity, and a much higher level of gut carboxypeptidase activity were found in field-collected western spruce budworm larvae.
...
PMID:Purification and characterization of the western spruce budworm larval midgut proteinases and comparison of gut activities of laboratory-reared and field-collected insects. 1038 Jun 52

Modulation of gut function is important in an ecological and evolutionary context because it likely determines what food items an animal can and cannot eat. We examined how diet affects activity of digestive enzymes in an omnivorous bird, the pine warbler (Dendroica pinus). Pine warblers were fed insect-based, fruit-based, and seed-based diets for approximately 54 d. We then measured activity of amylase, maltase, sucrase, aminopeptidase-N, trypsin, chymotrypsin, carboxypeptidase A, carboxypeptidase B, pancreatic lipase, and carboxyl ester lipase. We predicted that carbohydrase activities would be highest in birds fed the diet highest in carbohydrates (fruit based), protease activities would be highest in those fed the diet highest in protein (insect based), and lipase activities would be highest in those fed the diets highest in lipid (insect based and seed based). Also, we predicted that pine warblers would exhibit greater dietary modulation of enzyme activity than reported for a less omnivorous congener, the yellow-rumped warbler (Dendroica coronata). All predictions were upheld, supporting the hypothesis that pine warblers modulate the activity of digestive enzymes in proportion to demand from substrates in the diet.
...
PMID:An experimental test of dietary enzyme modulation in pine warblers Dendroica pinus. 1052 25

Midgut proteases contribute to the success or failure of Plasmodium infection of the mosquito. This paper examines the reciprocal effect of Plasmodium yoelii nigeriensis on midgut trypsin, chymotrypsin, aminopeptidase and carboxypeptidase in the mosquito Anopheles stephensi. The total protein ingested and the rate of protein digestion were unaffected by the parasite, but more protein was ingested at the first than the second bloodmeal. All peptidases were unaffected by the presence of the parasite during the first gonotrophic cycle, when ookinetes were penetrating the midgut. In the second gonotrophic cycle, trypsin and chymotrypsin were unaffected by growing oocysts, but aminopeptidase activity was reduced in the midguts of infected mosquitoes. Chymotrypsin activity was depressed and aminopeptidase activity elevated during the second gonotrophic cycle. Plasmodium infection has a negligible effect on bloodmeal digestion and does not limit the availability of the protein for egg production. The significance of changes in aminopeptidase activity when oocysts are present is discussed.
...
PMID:Blood digestion in the mosquito, Anopheles stephensi: the effects of Plasmodium yoelii nigeriensis on midgut enzyme activities. 1063 14

Extracts of Tyrophagus putrescentiae feces exhibited higher (>50-fold) specific protease activity rates than those measured using mite body extracts for the substrates azocasein, BApNa, SA(2)PPpNa, HA, and HPA. This suggests that trypsin, chymotrypsin, and carboxypeptidases A and B are involved in mite digestion. Hydrolysis of the substrates ZAA(2)MNA and LpNa was only 3 times higher in fecal extracts, suggesting that levels of cathepsin B and aminopeptidases in the lumen of the digestive tract are low compared to the other enzymes. The hydrolysis of hemoglobin was only detected in body extracts indicating that cathepsin D is not a digestive protease in this species. Protease inhibitors of different specificity were tested invivo to establish their potential as control agents. We found that development from larvae to adult was significantly retarded in larvae fed on brewers' yeast containing inhibitors of serine proteases, whereas no such effect was found with inhibitors of cysteine and aspartyl proteases. Interestingly, when dietary mixtures of serine protease, aminopeptidase and carboxypeptidase inhibitors were fed to T.putrescentiae, a synergistic effect was observed that retarded development. Several plant lectins were also tested, but none affected development.
...
PMID:Characterization of proteases from a stored product mite, Tyrophagus putrescentiae. 1068 99

The permeabilities of thyrotropin-releasing hormone (TRH) and insulin as model peptides were examined to characterize the tracheal epithelial barrier in in vitro experiments using excised rabbit trachea. TRH was not metabolized during 150 min duration of tracheal permeation and the apparent permeability coefficient (Papp) for TRH was about 3 x 10(-7) cm/s. The tracheal permeability of TRH was increased about three times by 10 mM glycocholate as a permeation enhancer. Insulin showed a slight degradation during 150 min duration of tracheal permeation, the Papp for insulin was 7 x 10(-9) cm/s. The tracheal permeability of insulin was significantly increased by 10 mM glycocholate, 1 mM bestatin (aminopeptidase B and leucine aminopeptidase inhibitor), and 10,000 KIU/ml aprotinin (trypsin and chymotrypsin inhibitor). The peptidase activities of rabbit tracheal epithelium were found to be the following; di-peptidyl-aminopeptidase IV (DPP IV) > Leu-aminopeptidase > cathepsin-B > trypsin. These activities were significantly lower than those of jejunal mucosal tissues. These results suggest that the tracheal absorption of peptide drugs through the respiratory tract may contribute to the systemic delivery of these drugs following the pulmonary administration of these drugs by intratracheal insufflation and instillation.
...
PMID:Effects of sodium glycocholate and protease inhibitors on permeability of TRH and insulin across rabbit trachea. 1081 42

Six decades of studies have speculated that digestive capacity might limit avian growth rate or that developmental changes in the gut might determine developmental changes in digestive efficiency. However, there are no studies on digestive enzymes during avian development, except for studies on mainly domestic birds that exhibit the precocial mode of development. We studied alimentary organ masses, intestinal enzyme activities (sucrase, maltase, isomaltase, aminopeptidase-N), and pancreatic enzyme activities (amylase, trypsin, chymotrypsin) during development of a wild passerine bird exhibiting the altricial mode of development. Wild nestling house sparrows were studied immediately after removal from the nest (days 0, 3, 6 of age; day 0=hatch), whereas captives were raised in the laboratory beginning day 3 on a formulated casein/starch-based diet until fledging age (after day 12). Digestive biochemistry was dynamic. Tissue-specific activities of some digestive enzymes continued to increase through fledging, by >10 times in some cases (e.g., sucrase and maltase in midintestine). Total pancreatic amylase activity increased 100 times between hatch and day 12 through a combination of increases in tissue-specific activity and pancreas mass. House sparrows differ from poultry, in whom after about 2 wk of age the specific activity of intestinal and pancreatic digestive enzymes is generally constant or declines during development. The data on intestinal and pancreatic enzymes help explain why digestive efficiency of nestling house sparrows improves with age, and the data seem consistent with the idea that digestive capacity might limit feeding rate and hence growth rate.
...
PMID:Developmental changes in digestive physiology of nestling house sparrows, Passer domesticus. 1151 62

Alcohol can be considered as a nutritional toxin when ingested in excess amounts and leads to skeletal muscle myopathy. We hypothesized that altered protease activities contribute to this phenomenon, and that differential effects on protease activities may occur when: (1) rats at different stages in their development are administered alcohol in vivo; (2) acute ethanol treatment is superimposed on chronic alcohol-feeding in vivo; and (3) muscles are exposed to alcohol and acetaldehyde in vivo and in vitro. In acute studies, rats weighing approximately 0.1 kg (designated immature) or approximately 0.25 kg (designated mature) body weight (BW) were dosed acutely with alcohol (75 mmol/kg BW; intraperitoneal [IP], 2.5 hours prior to killing) or identically treated with 0.15 mol/L NaCl as controls. In chronic studies, rats (approximately 0.1 kg BW) were fed between 1 to 6 weeks, with 35% of dietary energy as ethanol, controls were identically treated with isocaloric glucose. Other studies included administration of cyanamide (aldehyde dehydrogenase inhibitor) in vivo or addition of alcohol and acetaldehyde to muscle preparations in vitro. At the end of the treatments, cytoplasmic (alanyl-, arginyl-, leucyl-, prolyl-, tripeptidyl-aminopeptidase and dipeptidyl aminopeptidase IV), lysosomal (cathepsins B, D, H, and L, dipeptidyl aminopeptidase I and II), proteasomal (chymotrypsin-, trypsin-like, and peptidylglutamyl peptide hydrolase activities) and Ca(2+)-activated (micro- and milli-calpain and calpastatin) activities were assayed. (1) Acute alcohol dosage in mature rats reduced the activities of alanyl-, arginyl- and leucyl aminopeptidase (cytoplasmic), dipeptidyl aminopeptidase II (lysosomal), and the chymotrypsin- and trypsin-like activities (proteosomal). No significant effects were observed in similarly treated immature rats. (2) Alcohol feeding in immature rats did not alter the activities of any of the enzymes assayed at 6 weeks. (3) In immature rats, activities of cathepsins B and D were not overtly affected at either 3, 7, 14, 28, or 42 days. (4) Superimposing acute (2.5 hours) on chronic (4 weeks feeding of immature rats) ethanol treatment (ie, chronic + acute) reduced the activities of cytoplasmic proline aminopeptidase and the chymotrypsin- and trypsin-like activities of the proteasome. (5) Cathepsin D activities were reduced in muscle homogenates upon addition of alcohol and acetaldehyde in vitro. (6) Cyanamide pretreatment in combination with alcohol dosage in immature rats did not significantly alter any protease activities. The data suggests that mature rats are more sensitive to the effects of acute alcohol on muscle proteases. Protease activities may be affected by acetaldehyde or alcohol levels as indicated by in vitro experiments. The reduction in muscle protease activities in chronic + acute alcohol superimposition may reflect the effect of acute alcohol dosage alone. Overall, there was no evidence for increased protease activity in any of the experimental situations.
...
PMID:Effect of acute and chronic alcohol treatment and their superimposition on lysosomal, cytoplasmic, and proteosomal protease activities in rat skeletal muscle in vivo. 1178 79

The complete amino acid sequence of cassowary (Casuarius casuarius) goose type lysozyme was analyzed by direct protein sequencing of peptides obtained by cleavage with trypsin, V8 protease, chymotrypsin, lysyl endopeptidase, and cyanogen bromide. The N-terminal residue of the enzyme was deduced to be a pyroglutamate group by analysis with a LC/MS/MS system equipped with the oMALDI ionization source, and then confirmed by a glutamate aminopeptidase enzyme. The blocked N-terminal is the first reported in this enzyme group. The positions of disulfide bonds in this enzyme were chemically identified as Cys4-Cys60 and Cys18-Cys29. Cassowary lysozyme was proved to consist of 185 amino acid residues and had a molecular mass of 20408 Da calculated from the amino acid sequence. The amino acid sequence of cassowary lysozyme compared to that of reported G-type lysozymes had identities of 90%, 83%, and 81%, for ostrich, goose, and black swan lysozymes, respectively. The amino acid substitutions at PyroGlu1, Glu19, Gly40, Asp82, Thr102, Thr156, and Asn167 were newly detected in this enzyme group. The substituted amino acids that might contribute to substrate binding were found at subsite B (Asn122Ser, Phe123Met). The amino acid sequences that formed three alpha-helices and three beta-sheets were completely conserved. The disulfide bond locations and catalytic amino acid were also strictly conserved. The conservation of the three alpha-helices structures and the location of disulfide bonds were considered to be important for the formation of the hydrophobic core structure of the catalytic site and for maintaining a similar three-dimensional structure in this enzyme group.
...
PMID:The primary structure of cassowary (Casuarius casuarius) goose type lysozyme. 1186 97


<< Previous 1 2 3 4 5 6 7 Next >>

---