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

Fifty eight enterococcal isolates from wild herbivores were tested for their antibiotic sensitivity pattern and lectin-like binding of extracellular matrix (ECM) and serum proteins. Kanamycin resistance was very frequent; many multiresistant strains were also isolated. All isolates were sensitive to rifampicin. Resistance to gentamicin, novobiocin, and tetracycline was widely distributed in the microflora of wild herbivores breeded in zoological garden in Kosice. No autoaggregating strains were detected among these 58 enterococcal isolates. Various degrees of binding of mucins, fetuin, heparin, fibrinogen, and fibronectin were observed in individual strains. However, bovine lactoferrin binding by enterococci from deers and chamoises was either negative (0) or strongly positive (3). With regard to influence of growth media, TH agar was found to be better for the expression of lectin-like binding than blood agar, TH broth and Nutrient broth. A significant effect (P < 0.001 or P < 0.05) of proteolytic treatment was observed in six selected strains. However, there is a difference between the effect of trypsin and pronase P. Pronase treatment more effectively decreased binding of some strains (1H, 6A, EF 1111, EC 1292), while trypsin treatment decreased more binding of other enterococcal strains (EF 953 and 1E). Significant (P < 0.001) influence of metaperiodate, which cleaves the C-C bond between vicinal groups of sugars, on collagen I binding by three selected strains (1E, 1H, 6A) and bovine lactoferrin binding (by EF 1111, EC 1292, EF 953) was also observed. However, its influence was very different. In two strains (1H and EC 1292), ECM binding was decreased, while in four other strains (1E, 6A, EF 1111, EF 953) it was increased.
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PMID:Lectin-like binding and antibiotic sensitivity of enterococci from wild herbivores. 1250 93

Inhibitors of mast cell tryptase and chymase can be effective as mast cell stabilising compounds. Lactoferrin has been reported to inhibit tryptase activity, but its actions on other serine proteases of mast cells and its potential to alter mast cell function are not known. We have examined the ability of lactoferrin to inhibit mast cell tryptase, chymase and cathepsin G, and investigated its potential to modulate the activation of human mast cells. Enzymatically dispersed cells from human skin, lung and tonsil were challenged with anti-IgE or calcium ionophore A23187, following incubation with recombinant human lactoferrin, and histamine release determined. IgE-dependent histamine release from skin mast cells was inhibited by up to 50% following incubation with lactoferrin (50 or 500 nM). Tonsil mast cells were also stabilised by lactoferrin, but not those from lung. Calcium ionophore A23187-induced histamine release was not altered by lactoferrin. A double-labelling immunocytochemical procedure revealed the presence of lactoferrin in 4-6% of mast cells, and this proportion increased to 40% following incubation with lactoferrin. Lactoferrin did not inhibit cleavage of synthetic substrates by tryptase and chymase directly, though it was able to diminish the ability of heparin to stabilise tryptase. Cathepsin G activity was inhibited by lactoferrin. The ability of lactoferrin to inhibit IgE-dependent activation of human mast cells and modulate protease activity suggests that the release of this neutrophil product may have a role in the downregulation of allergic inflammation.
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PMID:The inhibition of mast cell activation by neutrophil lactoferrin: uptake by mast cells and interaction with tryptase, chymase and cathepsin G. 1262 33

Cells of the innate immune system and their mediators were studied at the single-cell level in the rectums of pediatric and adult patients with Shigella infection to better understand why children are at higher risk for severe infection. Adult patients had increased infiltration of mucosal mast cells (MMC) at the acute stage (3 to 5 days after the onset of diarrhea) and eosinophils in early convalescence (14 to 16 days after onset). Increased expression of stem cell factor and prostaglandin H synthase-1 (PGHS-1) was associated with increased tryptase-K(i)67-double-positive MMC in the acute stage and increased apoptosis of MMC, which led to a rapid decline in early convalescence. The eosinophils demonstrated increased expression of major basic protein (MBP), eotaxin, and CCR3, as well as increased necrotic death. The neutrophils showed enhanced alpha-defensin and lactoferrin expression in the acute phase. In contrast to adults, the pediatric patients demonstrated delayed accumulation of mast cells and eosinophils, while alpha-defensin expression persisted during convalescence. In contrast, neutrophil counts and lactoferrin expression were reduced in children compared to adults. The results suggest that children with shigellosis have a persistent activation of the innate immune response in the convalescent phase, indicating delayed elimination of Shigella antigens compared to adults.
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PMID:Persistence of mucosal mast cells and eosinophils in Shigella-infected children. 1270 43

Treponema have been implicated recently in the pathogenesis of digital dermatitis (DD) and contagious ovine digital dermatitis (CODD) that are infectious diseases of bovine and ovine foot tissues, respectively. Previous analyses of treponemal 16S rDNA sequences, PCR-amplified directly from DD or CODD lesions, have suggested relatedness of animal Treponema to some human oral Treponema species isolated from periodontal tissues. In this study a range of adhesion and virulence-related properties of three animal Treponema isolates have been compared with representative human oral strains of Treponema denticola and Treponema vincentii. In adhesion assays using biotinylated treponemal cells, T. denticola cells bound in consistently higher numbers to fibronectin, laminin, collagen type I, gelatin, keratin and lactoferrin than did T. vincentii or animal Treponema isolates. However, animal DD strains adhered to fibrinogen at equivalent or greater levels than T. denticola. All Treponema strains bound to the amino-terminal heparin I/fibrin I domain of fibronectin. 16S rDNA sequence analyses placed ovine strain UB1090 and bovine strain UB1467 within a cluster that was phylogenetically related to T. vincentii, while ovine strain UB1466 appeared more closely related to T. denticola. These observations correlated with phenotypic properties. Thus, T. denticola ATCC 35405, GM-1, and Treponema UB1466 had similar outer-membrane protein profiles, produced chymotrypsin-like protease (CTLP), trypsin-like protease and high levels of proline iminopeptidase, and co-aggregated with human oral bacteria Porphyromonas gingivalis and Streptococcus crista. Conversely, T. vincentii ATCC 35580, D2A-2, and animal strains UB1090 and UB1467 did not express CTLP or trypsin-like protease and did not co-aggregate with P. gingivalis or S. crista. Taken collectively, these results suggest that human oral-related Treponema have broad host specificity and that similar control or preventive strategies might be developed for human and animal Treponema-associated infections.
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PMID:Genetic relatedness and phenotypic characteristics of Treponema associated with human periodontal tissues and ruminant foot disease. 1272 70

Biological markers in nasal secretions provide valuable information on nasal pathophysiology. However, published data on biomarker concentrations in nasal fluids are remarkably inconsistent, and the bias due to different sampling techniques, has not yet been systematically evaluated. Concentrations of various protein were repeatedly determined in nasal secretions of 16 healthy volunteers. The proteins were detected by using: 1) alpha2-macroglobulin as a marker for plasma contamination; 2) lactoferrin as a marker for glandular secretion; 3) lactate dehydrogenase as a marker for tissue injury; and 4) interleukin (IL)-1beta, IL-8, tumour necrosis factor-alpha, and eosinophil cationic protein and tryptase as indicators for tissue inflammation. A total of four different sampling methods, including nasal lavage (NL) and a new polyurethane foam sampler technique (PFST) were employed. Analyte concentrations in NL were approximately 10-times lower than in specimens obtained by PFST. Due to the unpredictable dilution during NL, various analytes were below the detection limit of the high sensitivity assays employed. With PFST, concentrations below the detection limit rarely occurred. The specimens did not significantly differ regarding plasma contamination, glandular secretion or tissue injury. The considerable variability of reported analyte concentrations in nasal secretions mainly results from different sampling techniques. To collect nasal secretions, samplers are considered superior to nasal lavage techniques.
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PMID:Biological markers in nasal secretions. 1276 42

Milk forms a rich source of biologically interesting components. In particular, its protein fraction is known to encompass many kinds of biological functions. In this review we focus on antibacterial and antiviral properties of milk proteins and milk protein derivatives. The latter include chemically modified proteins and enzymatically induced peptides. If such peptides are released by enzymes present within the digestive tract (e.g. trypsin or pepsin), it is likely that they play a role in the health defense system. This is especially the case when the active fragments can survive the intestinal conditions long enough to arrive at the right place to exert their beneficial function. In the first part of this paper attention is paid to the antibacterial proteins lactoferrin, lactoperoxidase, and lysozyme. Furthermore, antibacterial peptides originating from caseins and whey proteins are described. The second part reports on studies of antiviral effects of milk proteins and derivatives thereof. Special focus is directed to the antiviral action towards the human immunodeficiency virus (HIV) and the human cytomegalovirus (HCMV). Unmodified milk proteins are generally not active against these viruses. An exception is lactoferrin, which shows significant antiviral activity against both HIV and HCMV. Several other milk proteins tested showed strong antiviral effects only after chemical modification, i.e. by making them polyanionic (for anti-HIV activity) or polycationic (for anti-HCMV activity). In a number of cases, conclusions are drawn concerning possible relationships between antibacterial/antiviral activity and molecular structure of the components described.
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PMID:Antibacterial and antiviral effects of milk proteins and derivatives thereof. 1276 35

We have compared the site-by-site N-glycosylation status of human lactoferrin (Lf) produced in maize, a monocotyledon, and in tobacco, used as a model dicotyledon. Maize and tobacco plants were stably transformed and recombinant Lf was purified from both seeds and leaves. N-glycopeptides were generated by trypsin digestion of recombinant Lf and purified by reverse-phase HPLC. The N-glycosylation pattern of each site was determined by mass spectrometry. Our results indicated that the N-glycosylation patterns of recombinant Lf produced in maize and tobacco share common structural features. In particular, both N-glycosylation sites of each recombinant Lf are mainly substituted by typical plant paucimannose-type N-glycans, with beta1,2-xylose and alpha1,3-linked fucose at the proximal N-acetylglucosamine. However, tobacco Lf shows a significant amount of processed N-glycans with one or two beta1,2GlcNAc linked to the trimannose core, which are weakly expressed in maize Lf. Finally, no Lewisa epitope was observed on tobacco Lf.
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PMID:Comparative analysis of the site-specific N-glycosylation of human lactoferrin produced in maize and tobacco plants. 1286 99

Hexahydrophthalic anhydride (HHPA), an industrially important chemical, is a highly allergenic compound. The aim of this work was to identify proteins in nasal lavage fluid (NLF) that form adducts with HHPA. Such bindings may induce production of specific immunoglobulin E (IgE) or affect physiological mechanisms of the proteins. NLF was obtained from HHPA-exposed volunteers, workers and exposed guinea pigs. HHPA-binding proteins were visualized with immunoblotting using a polyclonal antiserum against HHPA. The proteins were excised from sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) gels, digested with trypsin and identified by tandem mass spectrometry (MS/MS) and database searches. The antiserum was found to be specific for HHPA-bound proteins. In vivo formed HHPA-binding proteins in humans were identified as antileukoproteinase, immunoglobulin G (IgG), immunoglobulin A (IgA), serum albumin and lactoferrin. In addition, several proteins binding to HHPA were found in NLFs from guinea pigs but these could not be identified from database searches. Hypotheses for development of airways diseases by adduction of this allergenic compound to the NLF proteins in humans were established.
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PMID:In vivo conjugation of nasal lavage proteins by hexahydrophthalic anhydride. 1472 81

Lactoferrin (LF) is an iron-binding glycoprotein of the innate host defence system. To elucidate the role of N-linked glycosylation in protection of LF against proteolysis, we compared the tryptic susceptibility of human LF (hLF) variants from human milk, expressed in human 293(S) cells or in the milk of transgenic mice and cows. The analysis revealed that recombinant hLF (rhLF) with mutations Ile130-->Thr and Gly404-->Cys was about twofold more susceptible than glycosylated and unglycosylated variants with the naturally occurring Ile130 and Gly404. Hence, N-linked glycosylation is not involved in protection of hLF against tryptic proteolysis. Apparently, the previously reported protection by N-linked glycosylation of hLF [van Berkel, P.H.C., Geerts, M.E.J., van Veen, H.A., Kooiman, P.M., Pieper, F., de Boer, H.A. & Nuijens, J.H. (1995) Biochem. J. 312, 107-114] is restricted to rhLF containing the Thr130 and Cys404. Comparison of the tryptic proteolysis of hLF and bovine LF (bLF) revealed that hLF is about 100-fold more resistant than bLF. Glycosylation variants A and B of bLF differed by about 10-fold in susceptibility to trypsin. This difference is due to glycosylation at Asn281 in bLF-A. Hence, glycosylation at Asn281 protects bLF against cleavage by trypsin at Lys282.
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PMID:The role of N-linked glycosylation in the protection of human and bovine lactoferrin against tryptic proteolysis. 1476 83

Bovine lactoferrin catalyzes the hydrolysis of synthetic substrates (i.e., Z-aminoacyl-7-amido-4-methylcoumarin). Values of Km and kcat for the bovine lactoferrin catalyzed hydrolysis of Z-Phe-Arg-7-amido-4-methylcoumarin are 50 microM and 0.03 s(-1), respectively, the optimum pH value is 7.5 at 25 degrees C. The bovine lactoferrin substrate specificity is similar to that of trypsin, while the hydrolysis rate is several orders of magnitude lower than that of trypsin. The bovine lactoferrin catalytic activity is irreversibly inhibited by the serine-protease inhibitors PMSF and Pefabloc. Moreover, both iron-saturation of the protein and LPS addition strongly inhibit the bovine lactoferrin activity. Interestingly, bovine lactoferrin undergoes partial auto-proteolytic cleavage at positions Arg415-Lys416 and Lys440-Lys441. pKa shift calculations indicate that several Ser residues of bovine lactoferrin display the high nucleophilicity required to potentially catalyze substrate cleavage. However, a definitive identification of the active site awaits further studies.
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PMID:Proteolytic activity of bovine lactoferrin. 1522 73


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