Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Various parasites modify the immune-reactions of the host. We have previously shown that crude excretory/secretory (ES) products from plerocercoids of Spirometra erinaceieuropaei, the plerocercoids of which cause sparganosis in humans, suppress the expression of tumor necrosis factor (TNF)-alpha and IL-1beta in lipopolysaccharide (LPS)-stimulated macrophages. As osteoclasts are cells of the monocyte/macrophage lineage, we hypothesised that ES products might suppress receptor activator of nuclear factor kappaB ligand-induced osteoclastogenesis. Crude ES products from plerocercoids suppressed osteoclastogenesis, judged by tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cell counting, and the mature osteoclast-specific gene expression (calcitonin receptor and TRAP). Second, we purified the inhibitory factor for osteoclastogenesis from the crude ES products. The factor was a trypsin-sensitive glycoprotein and had a relative molecular mass of 90 kDa. The glycoprotein, plerocercoid-immunosuppressive factor, from crude ES products could suppress the gene expression of TNF-alpha, IL-1beta and NO synthesis in LPS-stimulated RAW264.7 macrophages.
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PMID:A glycoprotein from Spirometra erinaceieuropaei plerocercoids suppresses osteoclastogenesis and proinflammatory cytokine gene expression. 1605 Dec 45

Osteoclasts and macrophages express high amounts of tartrate-resistant acid phosphatase (TRACP), an enzyme with unknown biological function. TRACP contains a disulfide bond, a protease-sensitive loop peptide, and a redox-active iron that can catalyze formation of reactive oxygen species (ROS). We studied the effects of proteolytic cleavage by trypsin, reduction of the disulfide bond by beta-mercaptoethanol, and reduction of the redox-active iron by ascorbate on the phosphatase and ROS-generating activity of baculovirus-generated recombinant human TRACP. Ascorbate alone and trypsin in combination with beta-mercaptoethanol increased k(cat)/K(m) of the phosphatase activity seven- to ninefold. The pH-optimum was changed from 5.4-5.6 to 6.2-6.4 by ascorbate and trypsin cleavage. Trypsin cleavage increased k(cat)/K(m) of the ROS-generating activity 2.5-fold without affecting the pH-optimum (7.0). These results suggest that the protease-sensitive loop peptide, redox-active iron, and disulfide bond are important regulatory sites in TRACP, and that the phosphatase and ROS-generating activity are performed with different reaction mechanisms.
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PMID:Effects of proteolysis and reduction on phosphatase and ROS-generating activity of human tartrate-resistant acid phosphatase. 1662 Jul 68

Rat recombinant purple acid phosphatase (PAP) stably expressed in fibroblast-like CHO-K1 cells was purified and characterized with respect to post-translational modifications such as N-glycosylation and proteolytic processing in order to elucidate subcellular and molecular pathways for proteolytic activation. In these cells, proteolytically processed PAP was more abundant than the monomeric form. PAP-transfected CHO-K1 cells were expressing active cathepsin K intracellularly, which was partially co-localized with PAP. However, neither cathepsin K nor trypsin digestion of the purified monomeric PAP in vitro did result in a two-subunit form with kinetic and electrophoretic properties resembling the endogenous cellular two-subunit form. Treatment of PAP-transfected CHO-K1 cells with the cysteine proteinase inhibitor E-64 suggested that only a minor fraction of secreted PAP is processed intracellularly by cysteine proteinases. These data do not support a dominant or critical role for cathepsins or trypsin-like serine proteinases in the proteolytic activation of PAP in CHO-K1 cells, implicating yet unidentified proteinases in the proteolytic processing of both intracellular and secreted PAP in this cell line.
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PMID:Expression and proteolytic processing of mammalian purple acid phosphatase in CHO-K1 cells. 1732 76

Calcium binding peptides from Pacific cod (Gadus macrocephalus) bone have attracted attention due to their potential effects on bone health. In this study, calcium binding peptides (CBP) were prepared from Pacific cod bone by trypsin and neutral protease. Ultraviolet spectra, circular dichroism (CD), and Fourier transform infrared spectroscopy (FTIR) revealed that carboxyl and amino groups in CBP could bind to Ca2+, and form the peptide-calcium complex (CBP-Ca). Single-pass intestinal perfusion (SPIP) experiments indicated that the intestinal calcium absorption was significantly enhanced (p < 0.01) in CBP-Ca treated Wistar rats. The anti-osteoporosis activity of CBP-Ca was investigated in the ovariectomized (OVX) Wistar rat model. The administration of CBP-Ca significantly (p < 0.01) improved the calcium bioavailability, trabecular bone structure, bone biomechanical properties, bone mineral density, and bone mineralization degree. CBP-Ca notably (p < 0.01) increased serum calcium, however, it remarkably (p < 0.01) reduced the levels of osteocalcin (OCN), bone alkaline phosphatase (BALP), tartrate-resistant acid phosphatase isoform 5b (TRAP5b), and C-telopeptide of type I collagen (CTX-1) in serum. Results suggested that the cod bone derived CBP could bind with calcium, improve the intestinal calcium absorption, calcium bioavailability, and serum calcium, then reduce the bone turnover rate, and thus ameliorate osteoporosis.
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PMID:Functional Calcium Binding Peptides from Pacific Cod (Gadus macrocephalus) Bone: Calcium Bioavailability Enhancing Activity and Anti-Osteoporosis Effects in the Ovariectomy-Induced Osteoporosis Rat Model. 3023 72


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