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)

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

A cDNA encoding a chymotrypsinogen-like protein in midguts of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) was cloned and sequenced. The 901 bp cDNA contains an 816-nucleotide open reading frame encoding 272-amino acids. The predicted molecular mass and pI of the mature enzyme are 23.7 kDa and 4.64, respectively. The encoded protein includes amino acid sequence motifs that are conserved with 5 homologous chymotrypsinogen proteins from other insects. Features of the putative chymotrypsin-like protein from R. dominica include the serine proteinase active site (His(90), Asp(133), Ser(226)), conserved cysteine residues for disulfide bridges, the residues (Gly(220), Gly(243), Asp(252)) that determine chymotrypsin specificity, and both zymogen activation and signal peptides. A TPCK-sensitive caseinolytic protein (P6) with an estimated molecular mass of 24 kDa is present in midgut extracts of R. dominica and can be resolved by electrophoresis on 4-16% polyacrylamide gels. The molecular mass of this caseinolytic enzyme is similar to that of the chymotrypsin deduced from cDNA. Midgut extracts of R. dominica readily hydrolyzed azocasein and N-succinyl-alanine-alanine-proline-phenylalanine-p- nitroanilide (SAAPFpNA), a chymotrypsin-specific substrate. Properties of the enzymes responsible for these activities were partially characterized with respect to distribution in the gut, optimum pH, and sensitivity toward selected proteinase inhibitors. Optimal activity against both azocasein and SAAPFpNA occurs in a broad pH range from about 7 to 10. Both azocasein and SAAPFpNA activities, located primarily in the anterior midgut region, are inhibited by aprotinin, phenylmethyl sulphonylfluoride (PMSF), and soybean trypsin inhibitor (STI). TPCK (N-alpha-tosyl-L-phenylalanine chloromethyl ketone) and chymostatin inhibited more than 60% of SAAPFpNA but only about 10-20% of azocasein activity. These results provide additional evidence for the presence of serine proteinases, including chymotrypsin, in midguts of R. dominica. Arch. Insect Biochem. Physiol. 43:173-184, 2000.Published 2000 Wiley-Liss, Inc.
...
PMID:Molecular cloning and characterization of a midgut chymotrypsin-like enzyme from the lesser grain borer, Rhyzopertha dominica. 1073 21

Our previous studies have demonstrated that myoepithelial cells, which surround incipient carcinomas in situ of the breast and other organs, exert antiinvasive and antiangiogenic effects in vitro through the elaboration of a number of different suppressor molecules among which include the shed membrane CD44. The present study addresses the mechanism of this myoepithelial CD44 shedding. This CD44 shedding is enhanced by PMA pretreatment, is specific for myoepithelial CD44, and inhibited by chymotrypsin-like inhibitors (chymostatin, alpha(1)-antichymotrypsin, TPCK, and SCCA-2) but not by trypsin-like inhibitors (TLCK), nor papain-like inhibitors (SCCA-1) nor hydroxamate-based or general metalloproteinase inhibitors (BB2516 (marimastat), 1,10-phenanthroline, and TIMP-1). The effect of PMA can be mimicked by exogenous chymotrypsin but not by other proteases. The CD44 shedding activity cannot be transferred by conditioned media, cell-cell contact, peripheral membrane, or integral membrane fractions. However, cell-free purified integral plasma membrane fractions obtained from myoepithelial cells pretreated with PMA also exhibit CD44 shedding which is inhibited by chymotrypsin-like inhibitors. These findings support the presence and activation of a putative chymotrypsin-like sheddase as the mechanism of CD44 shedding in myoepithelial cells.
...
PMID:Myoepithelial-specific CD44 shedding is mediated by a putative chymotrypsin-like sheddase. 1111 26

Intra-acinar cell nuclear factor-kappaB (NF-kappaB) and trypsinogen activation are early events in secretagogue-induced acute pancreatitis. We have studied the relationship between NF-kappaB and trypsinogen activation in rat pancreas. CCK analogue caerulein induces early (within 15 min) parallel activation of both NF-kappaB and trypsinogen in pancreas in vivo as well as in pancreatic acini in vitro. However, NF-kappaB activation can be induced without trypsinogen activation by lipopolysaccharide in pancreas in vivo and by phorbol ester in pancreatic acini in vitro. Stimulation of acini with caerulein after 6 h of culture results in NF-kappaB but not trypsinogen activation. Protease inhibitors (AEBSF, TLCK, and E64d) inhibit both intracellular trypsin activity and NF-kappaB activation in caerulein stimulated acini. A chymotrypsin inhibitor (TPCK) inhibits NF-kappaB activation but not trypsin activity. The proteasome inhibitor MG-132 prevents caerulein-induced NF-kappaB activation but does not prevent trypsinogen activation. These findings indicate that although caerulein-induced NF-kappaB and trypsinogen activation are temporally closely related, they are independent events in pancreatic acinar cells. NF-kappaB activation per se is not required for the development of early acinar cell injury by supramaximal secretagogue stimulation.
...
PMID:Relationship between NF-kappaB and trypsinogen activation in rat pancreas after supramaximal caerulein stimulation. 1116 28

Persistent infection with hepatitis C virus (HCV) may lead to hepatocellular carcinoma (HCC). It has been suggested that HCV-encoded proteins are directly involved in the tumorigenic process. The HCV nonstructural protein NS3 has been identified as a virus-encoded serine protease. To study whether HCV NS3 has oncogenic activity, nontumorigenic rat fibroblast (RF) cells were stably transfected with an expression vector containing cDNA for the NS3 serine protease (nucleotides 3356-4080). The NS3 serine protease activity was determined in the transfected cells. The transfected cells grew rapidly and proliferated serum independently, lost contact inhibition, grew anchorage independently in soft agar and induced significant tumour formation in nude mice. Cells transfected with an expression vector containing a mutated NS3 serine protease (serine 139 to alanine at the catalytic site) showed no transforming abilities; their growth was dependent on serum and they did not grow anchorage independently in soft agar. Moreover, cells transfected with the NS3 serine protease and treated with the chymotrypsin inhibitors TPCK and PMSF (a serine protease inhibitor) lost their transforming feature. These results suggest that the NS3 serine protease of HCV is involved in cell transformation and that the ability to transform requires an active enzyme.
...
PMID:Cell transformation induced by hepatitis C virus NS3 serine protease. 1126 29

Lepidopteran insects like Helicoverpa zea and Agrotis ipsilon produce STI-insensitive trypsins in the midgut following ingestion of dietary plant proteinase inhibitors like STI [Broadway, R. M., J. Insect Physiol. 43(9) (1997) 855-874]. In this paper, the effects of dietary STI on a related family of midgut serine proteinases, the chymotrypsins, were investigated. STI-insensitive midgut chymotrypsins were detected in larvae of H. zea and A. ipsilon feeding on diets containing 1% STI while STI-sensitive chymotrypsins were present in larvae feeding on diets containing 0% STI. These chymotrypsins were unaffected by TPCK, a diagnostic inhibitor of mammalian chymotrypsins but were fully inhibited by chymostatin. Four midgut cDNA libraries were constructed from larvae of each species fed either 0% STI or 1% STI diets. Six full-length cDNAs(1) encoding diverse preprochymotrypsins were isolated (three from H. zea and three from A. ipsilon) with certain sequence motifs that set them apart from their mammalian counterparts. Northern blots showed that some chymotrypsin mRNA were detected at higher levels while others were down-regulated when comparing insects reared on 0% STI and 1% STI diets. Southern hybridizations suggested that (like mammals) both species contained several chymotrypsin genes. A full-length chymotrypsin gene(1) from H. zea was sequenced for the first time and the presence of four introns was deduced. A first time comparison of 5' upstream regions(1) from three chymotrypsin genes and two trypsin genes of A. ipsilon indicated the presence of putative TATA boxes and regulatory elements. However a lack of consensus motifs in these upstream regions suggested the likelihood of multiple trans factors for regulation of genes encoding digestive proteinases and a complex response mechanism linked to ingestion of proteinase inhibitors.
...
PMID:Identification of six chymotrypsin cDNAs from larval midguts of Helicoverpa zea and Agrotis ipsilon feeding on the soybean (Kunitz) trypsin inhibitor. 1126 2

The present study describes the activity and some characteristics of proteinases in the hepatopancreas of red shrimp Pleoticus muelleri during the different stages of the molting cycle. Proteolytic activity was highest between pH 7.5 and 8. The hepatopancreatic protein content in the premolt stage was higher than in the other stages of the molting cycle (P<0.05). No significant differences were found in total proteolytic activity in the hepatopancreas when comparing molting stages. The proteolytic activity of the P. muelleri hepatopancreas enzyme preparations is the main responsibility of serine proteinases. TLCK, a trypsin inhibitor, reduced azocasein hydrolysis between 26% (intermolt) and 37% (premolt). TPCK, a chymotrypsin inhibitor, did not decrease hydrolytic activity, except for in postmolt. Low trypsin and chymotrypsin activities were found during intermolt, and increased in postmolt. The electrophoretogram of the enzyme extracts shows 12 bands of activity during intermolt (from 16.6 to 53.1 kDa). Some fractions were not detected in the postmolt and premolt stages. Three low molecular weight trypsin forms (17.4, 19.1 and 20 kDa) were found in all molting stages. One band of chymotrypsin (21.9 kDa) was observed in all molting stages. High molecular mass active bands (66-205 kDa) could not be characterized with inhibitors. Comparison of the protease-specific activity of the hepatopancreas of some species indicated a relationship between digestive enzyme activity and feeding habits of the shrimp. Omnivorous shrimp, such as Penaeus vannamei (syn: Litopenaeus vannamei) and Penaeus monodon, showed higher protease activity than the carnivorous shrimp, Penaeus californiensis (syn: Farfantepenaeus californiensis) and P. muelleri. In fact, the enzymatic activity in the hepatopancreas of P. muelleri showed variations in relation to feeding habit and molting cycle.
...
PMID:Digestive proteinases of red shrimp Pleoticus muelleri (Decapoda, Penaeoidea): partial characterization and relationship with molting. 1156 95

Two novel extracellular serine proteases were purified to homogeneity from the cell-free culture filtrate of an obligate alkalophilic Bacillus sphaericus by a combination of ultrafiltration, ammonium sulfate precipitation and chromatographic methods. The enzymes showed similar substrate specificities, but differed in hydrophobicity and molecular mass. Protease A was a monomeric protease with a relative molecular mass (M(r)) of 28.7 kDa, whereas protease B, with a M(r) of 68.0 kDa, apparently consisted of smaller subunits. The purified protease A had a specific activity on hemoglobin of 5.1 U/mg protein compared to 40.9 U/mg protein in the case of protease B. Both proteases were most active on SAAPF-pNa, a substrate for chymotrypsin-like serine proteases. However, the K(m) values of these two proteases on SAAPF-pNa were higher than that for alpha-chymotrypsin, indicating a lower affinity of proteases A and B for this substrate compared to chymotrypsin. Unlike other Bacillus serine proteases, neither protease A nor B stained with Coomasie blue R-250, even with loading of a large amount of protein, and they stained poorly with the silver staining method. However, NH(2)-terminal amino acid sequencing of protease B revealed a high similarity with subtilisin Carlsberg (67% homology). Almost total inhibition of both proteases by PMSF, but very little/no inhibition by trypsin and chymotrypsin inhibitors (TPCK and TLCK) or thiol reagents (PCMB and iodoacetic acid), further supported the view that the enzyme belonged to the serine protease family.
...
PMID:Purification and characterization of two extracellular alkaline proteases from a newly isolated obligate alkalophilic Bacillus sphaericus. 1157 23

Foot-and-mouth disease virus is a highly contagious pathogen that spreads rapidly among livestock and is capable of causing widespread agricultural and economic devastation. The virus genome is translated to produce a single polypeptide chain that subsequently is cleaved by viral proteases into mature protein products, with one protease, 3C(pro), carrying out the majority of the cleavages. The highly conserved nature of this protease across different viral strains and its crucial role in viral maturation and replication make it a very desirable target for inhibitor design. However, the lack of a convenient and high-throughput assay has been a hindrance in the characterization of potential inhibitors. In this article, we report the development of a continuous assay with potential for high throughput using fluorescence resonance energy transfer-based peptide substrates. Several peptide substrates containing the 3C-specific cleavage site were synthesized, varying both the positions and separation of the fluorescent donor and quencher groups. The best substrate, with a specificity constant k(cat)/K(M) of 57.6+/-2.0M(-1) s(-1), was used in inhibition assays to further characterize the protease's activity against a range of commercially available inhibitors. The inhibition profile of the enzyme showed characteristics of both cysteine and serine proteases, with the chymotrypsin inhibitor TPCK giving stoichiometric inhibition of the enzyme and allowing active site titration of the 3C(pro).
...
PMID:A continuous assay for foot-and-mouth disease virus 3C protease activity. 1763 55

Acrosomal proteases allow the spermatozoon not only to cross the cumulus cells and penetrate the zona pellucida of the oocyte, but also they are needed for the acrosome reaction process (AR). The present study evaluated in vitro the role of trypsin and chymotrypsin in the acrosome reaction of canine spermatozoa by means of protease inhibitors. Spermatozoa obtained from the second fraction of the ejaculate and devoid of seminal plasma were re-suspended in canine capacitation medium (CCM) and incubated at 38.5 degrees C in 5% CO(2). After 2 h (period of sperm capacitation), aliquots of sperm suspension were incubated separately with trypsin inhibitor NPGB (p-nitrophenyl-p'-guanidino-benzoate); TI (Trypsin inhibitor I-S Type from soybean) and with chymotrypsin inhibitor TPCK (N-tosyl-L-phenylalanine-chloromethyl-ketone) for 30 min. The AR was induced with progesterone and evaluated using the dual fluorescent staining technique 'Hoechst and chlortetracycline'. Acrosomal exocytosis levels were statistically significant higher in the samples treated with progesterone than in the control without inducer. However, the trypsin inhibitors NPGB, TI and the chymotrypsin inhibitor TPCK reduced the percentage of AR when compared with the control with progesterone and without inhibitor (p < 0.001), where the AR values were 45.63 +/- 3.8%, 51.63 +/- 2.8%, 58.38 +/-4.1% and 71.25 +/- 4.9%, respectively. These results show that trypsin and chymotrypsin inhibitors are effective in blocking the acrosome reaction induced by progesterone in canine; in addition, they suggest the participation of respective proteases in the AR process in this species.
...
PMID:Trypsin and chymotrypsin are involved in the progesterone-induced acrosome reaction in canine spermatozoa. 1895 92


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

---