Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has traditionally been believed that only the human collagenases (matrix metalloproteinase-1, -8, and -13) are capable of initiating the degradation of collagens. Here, we show that human trypsin-2 is also capable of cleaving the triple helix of human cartilage collagen type II. We purified human trypsin-2 and tumor-associated trypsin inhibitor by affinity chromatography whereas collagen type II was purified from cartilage extracts using pepsin digestion and salt precipitation. Degradation of type II collagen and gelatin by trypsin-2 was demonstrated with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, zymography, and mass spectrometry, and tumor-associated trypsin inhibitor specifically inhibited this degradation. Although human trypsin-2 efficiently digested type II collagen, bovine trypsin did not. Furthermore, immunohistochemical staining detected trypsin-2 in the fibroblast-like synovial lining and in stromal cells of human rheumatoid arthritis synovial membrane. These findings were confirmed by reverse transcriptase-polymerase chain reaction and nucleotide sequencing. Trypsin-2 alone and complexed with alpha(1)-proteinase inhibitor were also detected in the synovial fluid of affected joints by time-resolved immunofluorometric assay, suggesting that trypsin-2 is activated locally. These results are the first to assess the ability of human trypsin to cleave human type II collagen. Thus, trypsin-2 and its regulators should be further studied for use as markers of prognosis and disease activity in rheumatoid arthritis.
 ...
PMID:Trypsin-2 degrades human type II collagen and is expressed and activated in mesenchymally transformed rheumatoid arthritis synovitis tissue. 1619 46

Antifungal peptides with a molecular mass of 9 kDa and an N-terminal sequence demonstrating remarkable similarity to those of nonspecific lipid transfer proteins (nsLTPs) were isolated from seeds of the vegetable Brassica campestris and the mung bean. The purified peptides exerted an inhibitory action on mycelial growth in various fungal species. The antifungal activity of Brassica and mung bean nsLTPs were thermostable, pH-stable, and stable after treatment with pepsin and trypsin. In contrast, the antifungal activity of mung bean chitinase was much less stable to changes in pH and temperature. Brassica LTP inhibited proliferation of hepatoma Hep G2 cells and breast cancer MCF 7 cells with an IC(50) of 5.8 and 1.6 microM, respectively, and the activity of HIV-1 reverse transcriptase with an IC(50) of 4 microM. However, mung bean LTP and chitinase were devoid of antiproliferative and HIV-1 reverse transcriptase inhibitory activities. In contrast to the mung bean LTP, which exhibited antibacterial activity, Brassica LTP was inactive. All three antifungal peptides lacked mitogenic activity toward splenocytes. These results indicate that the two LTPs have more desirable activities than the chitinase and that there is a dissociation between the antifungal and other activities of these antifungal proteins.
 ...
PMID:Lipid transfer proteins from Brassica campestris and mung bean surpass mung bean chitinase in exploitability. 1772 19

Celiac disease (CD) is a chronic enteropathy triggered by intake of gliadin, the toxic component of gluten. This study aims at evaluating the capacity of different Bifidobacterium strains to counteract the inflammatory effects of gliadin-derived peptides in intestinal epithelial (Caco-2) cells. A commercial extract of several gliadin (Gld) types (alpha, beta, gamma, [symbol: see text] ) was subjected to in vitro gastrointestinal digestion (pepsin at pH 3, pancreatin-bile at pH 6), inoculated or not with cell suspensions (10(8) colony forming units/ml) of either B. animalis IATA-A2, B. longum IATA-ES1, or B. bifidum IATA-ES2, in a bicameral system. The generated gliadin-derived peptides were identified by reverse phase-HPLC-ESI-MS/MS. Caco-2 cell cultures were exposed to the different gliadin peptide digestions (0.25 mg protein/ml), and the mRNA expression of nuclear factor kappa-B (NF-kappaB), tumor necrosis factor alpha (TNF-alpha), and chemokine CXCR3 receptor were analyzed by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) in stimulated cells. The production of the pro-inflammatory markers NF-kappaB p50, TNF-alpha, and IL-1beta (interleukine 1beta) by Caco-2 cells was also determined by ELISA. The peptides from gliadin digestions inoculated with bifidobacteria did not exhibit the toxic amino acid sequences identified in those noninoculated (alpha/beta-Gld [158-164] and alpha/beta-Gld [122-141]). The RT-PCR analysis evidenced a down-regulation in mRNA expression of pro-inflammatory biomarkers. Consistent with these results the production of NF-kappaB, TNF-alpha, and IL-1beta was reduced (18.2-22.4%, 28.0-64.8%, and abolished, respectively) in cell cultures exposed to gliadin digestions inoculated with bifidobacteria. Therefore, bifidobacteria change the gliadin-derived peptide pattern and, thereby, attenuate their pro-inflammatory effects on Caco-2 cells.
 ...
PMID:Bifidobacteria inhibit the inflammatory response induced by gliadins in intestinal epithelial cells via modifications of toxic peptide generation during digestion. 2005 69

The antiretroviral is a non-nucleoside reverse transcriptase inhibitor of human immunodeficiency virus type 1. This study was undertaken to investigate the effect of nevirapine (NVP) administration on gastric acid secretion, pepsin secretion, mucosal secretion, intestinal motility, and transit using apparently healthy albino Wistar rats. Eighty albino Wistar rats (50-125 g body weight) from the start of the experiment were used for the study. Rats in the control group were fed normal rodent chow, while the NVP group was fed by gavage NVP (0.4 mg/kg body weight) two times daily (07:00 and 18:00 hours) in addition to normal rodent chow for 12 weeks. All animals were allowed free access to clean drinking water. Mean basal gastric output and peak acid output following histamine administration in the NVP-treated group were significantly higher (p < 0.001, respectively) compared to the control. Following cimetidine administration, there was significant decrease (p < 0.001) in peak acid output in the NVP-treated group compared to the control. The concentration of gastric pepsin, adherent mucus secretion, and mean value for ulcer score were significantly higher (p < 0.001) compared to their control group, respectively. There were significant increases (p < 0.05, respectively) in intestinal motility and basal contraction (p < 0.05) and increase in intestinal transit of the ileum of NVP-treated rats compared to their control, respectively. Results of the study suggest that NVP administration might provoke gastric ulceration in rats which may be caused by high pepsin, high basal acid output, and increased intestinal motility and transit.
 ...
PMID:Ulcerogenic and intestinal motility/transit stimulating actions of nevirapine in albino Wistar rats. 2353 14


<< Previous 1 2