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)

Proteases capable of activating procollagenase from gingiva and from fibroblast and macrophage monolayer cultures were harvested from homogenates of canine tumor mast cells. The mast cell proteases lysed casein and Azocoll but not native collagen. In low salt concentrations the enzymes existed at high molecular weight complexes, which were dissociated by increasing the salt concentration above 1.0 M (NaCl, KCl). Gel filtration in 1.4 M KCl separated the protease activity into three peaks, all of which activated procollagenase. Two of the enzymes showed substrate specificities (hydrolysis of p-tosyl-L-arginine methyl ester and benzoyl-tyrosine ethyl ester) and reactive center reactivities similar to pancreatic trypsin and chymotrypsin. Based on gel filtration, apparent molecular weights of 160 000 (p-tosyl-L-arginine methyl ester esterase), 90 000 (main procollagenase activator) and 36 000 benzoyl-tyrosine ethyl ester esterase) were determined. Activation of procollagenase resulted in a 18-20 000 decrease of the molecular weight. The activation was directly related to the amount of activator added within certain limits. Further addition of activator resulted in proteolytic inactivation of collagenase.
...
PMID:Activation of fibroblast procollagenase by mast cell proteases. 5 9

Neutral proteoglycanase and other protease activity from cellular and CM fractions of monolayer-cultured rabbit articular chondrocytes were studied. The cellular fraction comprising soluble cytoplasmic enzymes possessed concentration-dependent elastase-like esterase activity and activity against trypsin and chymotrypsin synthetic substrates but had little caseinase activity. The 20% ammonium sulfate precipitate of CM possessed more neutral caseinase activity than the 60% ammonium sulfate precipitate and the bulk of activity against the synthetic substrates. Activity against bovine nasal septum PG was present in these fractions. Both the 20% and 60% ammonium sulfate fractions reduced the viscosity and the S of the PG substrate. This activity was incompletely inhibited by preincubation with either 5 mM o-phenanthroline or 10 mM EDTA, indicating that it was paritally metal-dependent. The activity in the cellular fraction was also partially inhibited by o-phenanthroline but more so by EDTA. These data indicate that chondrocytes synthesize and secrete into the culture medium neutral proteoglycanase(s) capable of initiating degradation of PG derived from the neutral pH cartilage matrix. The inhibitory profiles, together with recent evidence of enzymes with similar activity extracted from cartilage suggested that the proteoglycanase enzyme(s) may occur in multiple forms.
...
PMID:Metal-dependent neutral proteoglycanase activity from monolayer-cultured lapine articular chondrocytes. 43 3

Monoclonal antibodies were raised that specifically recognize the NH2-terminal neoepitope sequence present in link protein cleavage products derived from stromelysin-degraded proteoglycan aggregate. Competitive enzyme-linked immunosorbent assay, using synthetic peptides as inhibitors, showed that one of these antibodies (CH-3) required, for antibody recognition, the free NH2-terminal amino acid isoleucine (residue 17 of the intact protein) in the sequence NH2-IQAENG at the stromelysin cleavage site of link protein 3. Human proteoglycan aggregate was digested with recombinant human stromelysin, bovine chymotrypsin, bovine trypsin, and porcine elastase, and their respective link protein degradation products were tested for immunoreactivity with antibody CH-3. Only stromelysin- and chymotrypsin-generated link protein 3 were recognized by antibody CH-3. Both of these enzymes generate link protein NH2 termini with the sequence 17IQAENG. . .; hence these studies indicated that monoclonal antibody CH-3 recognized this neoepitope sequence in only specific proteolytically modified link protein molecules. Since the occurrence of link protein 3 increases with aging, the incidence of CH-3 epitope in proteoglycans isolated from human knee articular cartilage of individuals of different ages was investigated. The prevalence of CH-3 epitope was found to be highest in newborn and adolescent articular cartilage samples. However, little CH-3 epitope was detected in older adult cartilage, although considerably more link protein 3 was present in these samples. These results suggest that additional proteolytic agents are responsible for the increased occurrence of link protein degradation products with aging.
...
PMID:Monoclonal antibodies recognizing protease-generated neoepitopes from cartilage proteoglycan degradation. Application to studies of human link protein cleavage by stromelysin. 137 86

Matrix metalloproteinase 9 (MMP-9) has been purified as an inactive zymogen of M(r) 92,000 (proMMP-9) from the culture medium of HT 1080 human fibrosarcoma cells. The NH2-terminal sequence of proMMP-9 is Ala-Pro-Arg-Gln-Arg-Gln-Ser-Thr-Leu-Val-Leu-Phe-Pro, which is identical to that of the 92-kDa type IV collagenase/gelatinase. The zymogen can be activated by 4-aminophenylmercuric acetate, yielding an intermediate form of M(r) 83,000 and an active species of M(r) 67,000, the second of which has a new NH2 terminus of Met-Arg-Thr-Pro-Arg-(Cys)-Gly-Val-Pro-Asp-Leu-Gly-Arg-Phe-Gln-Thr- Phe-Glu. Immunoblot analyses demonstrate that this activation process is achieved by sequential processing of both NH2- and COOH-terminal peptides. TIMP-1 complexed with proMMP-9 inhibits the conversion of the intermediate form to the active species of M(r) 67,000. The proenzyme is fully activated by cathepsin G, trypsin, alpha-chymotrypsin, and MMP-3 (stromelysin 1) but not by plasmin, leukocyte elastase, plasma kallikrein, thrombin, or MMP-1 (tissue collagenase). During the activation by MMP-3, proMMP-9 is converted to an active species of M(r) 64,000 that lacks both NH2- and COOH-terminal peptides. In addition, HOCl partially activates the zymogen by reacting with an intermediate species of M(r) 83,000. The enzyme degrades type I gelatin rapidly and also cleaves native collagens including alpha 2 chain of type I collagen, collagen types III, IV, and V at undenaturing temperatures. These results indicate that MMP-9 has different activation mechanisms and substrate specificity from those of MMP-2 (72-kDa gelatinase/type IV collagenase).
...
PMID:Matrix metalloproteinase 9 (92-kDa gelatinase/type IV collagenase) from HT 1080 human fibrosarcoma cells. Purification and activation of the precursor and enzymic properties. 140 Apr 81

Procollagenase M(r) 85,000 (SDS-PAGE) was purified from buffy coat to homogeneity and represents a stable single polypeptide chain forming the entire proenzyme. The procollagenase can be activated by various proteinases, e.g. trypsin, chymotrypsin, cathepsin G, kallikrein and stromelysin and by different mercurial compounds. Proteolytic conversion of the latent enzyme to the active form by chymotrypsin is accompanied by a molecular weight reduction to an apparent M(r) 64,000. This active enzyme lacks the first 79 N-terminal residues. Activation by trypsin leads to a latent intermediate of apparent M(r) 70,000, lacking 48 N-terminal residues. The active enzyme is therefore generated upon prolonged incubation with trypsin by further cleavage of 22 N-terminal residues. Another latent intermediate form with apparent M(r) 69,000 is generated from the proenzyme upon incubation with leukocyte elastase by N-terminal cleavage of 53 or 64 residues, respectively. However, latent collagenase cannot be activated by plasmin. Activation by different mercurial compounds finally results in the formation of active collagenase with apparent M(r) 64,000. In contrast to the proenzyme, active collagenase can autolyse to give active M(r) 57,000 and 45,000 intermediates and two M(r) 28,000 fragments. Purification of latent leukocyte gelatinase yields three final products with apparent M(r) 98,000, 125,000 and 220,000 (SDS-PAGE; non reduced). Upon reduction, only the M(r) 98,000 form can be detected. The latent gelatinase can be activated in a similar manner as collagenase. Proteolytic activation by trypsin leads after N-terminal cleavage to an active gelatinase with sequence homology to leukocyte collagenase.
...
PMID:Latent collagenase and gelatinase from human neutrophils and their activation. 148 34

Human rheumatoid synovial cells in culture secrete at least three related metalloproteinases that digest extracellular matrix macromolecules. One of them, termed matrix metalloproteinase 2 (MMP-2), has been purified as an inactive zymogen (proMMP-2). The final product is homogeneous on SDS/PAGE with Mr = 72,000 under reducing conditions. The NH2-terminal sequence of proMMP-2 is Ala-Pro-Ser-Pro-Ile-Ile-Lys-Phe-Pro-Gly-Asp-Val-Ala-Pro-Lys-Thr, which is identical to that of the so-called '72-kDa type IV collagenase/gelatinase'. The zymogen can be rapidly activated by 4-aminophenylmercuric acetate to an active form of MMP-2 with Mr = 67,000, and the new NH2-terminal generated is Tyr-Asn-Phe-Phe-Pro-Arg-Lys-Pro-Lys-Trp-Asp-Lys-Asn-Gln-Ile. However, following 4-aminophenylmercuric acetate activation, MMP-2 is gradually inactivated by autolysis. Nine endopeptidases (trypsin, chymotrypsin, plasmin, plasma kallikrein, thrombin, neutrophil elastase, cathepsin G, matrix metalloproteinase 3, and thermolysin) were tested for their abilities to activate proMMP-2, but none had this ability. This contrasts with the proteolytic activation of proMMP-1 (procollagenase) and proMMP-3 (prostromelysin). The optimal activity of MMP-2 against azocoll is around pH 8.5, but about 50% of activity is retained at pH 6.5. Enzymic activity is inhibited by EDTA, 1,10-phenanthroline or tissue inhibitor of metalloproteinases, but not by inhibitors of serine, cysteine or aspartic proteinases. MMP-2 digests gelatin, fibronectin, laminin, and collagen type V, and to a lesser extent type IV collagen, cartilage proteoglycan and elastin. Comparative studies on digestion of collagen types IV and V by MMP-2 and MMP-3 (stromelysin) indicate that MMP-3 degrades type IV collagen more readily than MMP-2, while MMP-2 digests type V collagen effectively. Biosynthetic studies of MMPs using cultured human rheumatoid synovial fibroblasts indicated that the production of both proMMP-1 and proMMP-3 is negligible but it is greatly enhanced by the treatment with rabbit-macrophage-conditioned medium, whereas the synthesis of proMMP-2 is constitutively expressed by these cells and is not significantly affected by the treatment. This suggests that the physiological and/or pathological role of MMP-2 and its site of action may be different from those of MMP-1 and MMP-3.
...
PMID:Matrix metalloproteinase 2 from human rheumatoid synovial fibroblasts. Purification and activation of the precursor and enzymic properties. 226 96

The mechanisms of activation of the precursor of human matrix metalloproteinase 3 (proMMP-3/prostromelysin) by proteinases and (4-aminophenyl)mercuric acetate (APMA) were investigated by kinetic and sequence analyses. Incubation of proMMP-3 with neutrophil elastase, plasma kallikrein, plasmin, or chymotrypsin at 37 degrees C resulted in the formation of MMP-3 of Mr = 45,000 by cleaving of the His82-Phe83 bond. Since this bond is unlikely to be cleaved by these proteinases it was postulated that an initial attack of an activator proteinase on proMMP-3 creates an intermediate form, which is then processed to a more stable form of Mr = 45,000. To test this hypothesis proMMP-3 was incubated with these serine proteinases under conditions that minimize the action of MMP-3. This led to the accumulation of major intermediates of Mr = 53,000 and two minor forms of Mr = 49,000 and 47,000. The 53,000 Mr intermediate generated by human neutrophil elastase resulted from cleavage of the Val35-Arg36 whereas plasma kallikrein cleaved the Arg36-Arg37 and Lys38-Asp39 bonds and chymotrypsin the Phe34-Val35 bond, all of which are located near the middle of the propeptide. Conversion of these intermediates to the fully active 45,000 Mr form of MMP-3 resulted from a bimolecular reaction of the intermediates. A similar short-lived intermediate of Mr = 46,000 generated by APMA was a result of the intramolecular cleavage of the Glu68-Val69 bond, and it was then converted to a stable MMP-3 of Mr = 45,000 by a intermolecular reaction of MMP-3. However, MMP-3 failed to activate proMMP-3.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Stepwise activation mechanisms of the precursor of matrix metalloproteinase 3 (stromelysin) by proteinases and (4-aminophenyl)mercuric acetate. 238 57

Tissue inhibitor of metalloproteinases (TIMP) from cultured bovine dental pulp inhibits human rheumatoid synovial matrix metalloproteinase 3 (MMP-3) with a stoichiometry of 1:1 on a molar basis. Among the serine proteinases examined, human neutrophil elastase, trypsin and alpha-chymotrypsin destroyed the inhibitory activity of TIMP against MMP-3 by degrading the inhibitor molecule into small fragments. In contrast, the inhibitory activity of TIMP was not significantly reduced by the actions of cathepsin G, pancreatic elastase and plasmin. These data indicate that neutrophils which infiltrate tissues in various inflammatory conditions may play an important role in regulating TIMP activity in vivo through the action of neutrophil elastase.
...
PMID:Inactivation of tissue inhibitor of metalloproteinases by neutrophil elastase and other serine proteinases. 316 16

Monolayer and spinner cultured rabbit articular chondrocytes released into the medium latent metal-dependent enzyme with activity against bovine proteoglycan. Pretreatment of medium with p-aminophenylmercuric acetate or trypsin followed by soybean trypsin inhibitor significantly increased enzyme activity. The monolayer-cultured chondrocytes released more of this activity than spinner cultures. The neutral proteoglycanase activity increased with medium concentration and incubation time. Like the human cartilage proteoglycanase, its pH optimum on proteoglycan subunit was 7.25. Gel filtration on BioGel P-30 indicated that the proteoglycanase occurred in two molecular weight forms: 20 000--30 000 and 13 000. The latent enzyme was about 30 000--40 000. The metal-chelators, o-phenanthroline (5 mM) and EDTA (10 mM) inhibited the activated proteoglycanase almost completely, but trypsin and chymotrypsin inhibitors had little effect. The cultured chondrocytes also released into the media a heat-labile inhibitor against the proteoglycanase. The inhibitory activity was present in the nonactivated media and eluted on Sephadex G-100 chiefly at a position corresponding to molecular weights of 10 000--13 000.
...
PMID:Neutral proteinases from articular chondrocytes in culture. 2. Metal-dependent latent neutral proteoglycanase, and inhibitory activity. 678 2

Primitive biliary cells are known to migrate from the ductal plate into the mesenchyme during human intrahepatic bile duct development, and this migration process is essential for normal development of intrahepatic bile ducts. However, its molecular mechanism is unknown. Matrix proteinases play an important role in cell migration during cancer invasion and organ development. In this study, we therefore investigated in situ expression of matrix metalloproteinases (MMP) and tissue inhibitors of MMP (TIMP) during human intrahepatic bile duct development, using 32 human fetal livers. We also examined in situ expression of trypsinogen/trypsin, chymotrypsinogen/chymotrypsin, and cathepsin B, which are matrix proteinases and activators of MMP. MMP-1 expression was noted in the ductal plate and migrating primitive biliary cells. MMP-2, MMP-3, and MMP-9 were expressed in the ductal plate. TIMP-1 and TIMP-2 were expressed in the ductal plate and migrating primitive biliary cells. Trypsinogen/trypsin, chymotrypsinogen/chymotrypsin, and cathepsin B were also expressed in primitive biliary cells. These data suggest that MMP, trypsinogen/trypsin, chymotrypsinogen/chymotrypsin, and cathepsin B play a critical role in biliary cell migration during human intrahepatic bile duct development by degrading extracellular matrix proteins. The data also suggest that MMP inhibitors (TIMP-1 and TIMP-2) and MMP activators (trypsin, chymotrypsin, and cathepsin B) play an important role in biliary cell migration. The coordinated expression of MMP, MMP inhibitors, and MMP activators may be necessary for the normal development of human intrahepatic bile ducts.
...
PMID:Expression of matrix proteinases during human intrahepatic bile duct development. A possible role in biliary cell migration. 748 84


1 2 Next >>

---