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)

The aim of the present study was to describe the physicochemical characteristics of streptococcal T antigen. T protein isolated from Streptococcus pyogenes type 12 (R53/1077, Colindale) and purified by ion-exchange column chromatography resulted in a preparation that was homogeneous when tested electrophoretically (in two systems, in presence and in absence of sodium dodecyl sulfate) and by gel filtration on Sephadex G-100. The purified T antigen was resistant to enzymatic degradation by trypsin and pepsin. It formed a single precipitin line with standard T-12 antiserum and was not contaminated with group A carbohydrate and M protein. The molecular weight of protein T, determined by means of polyacrylamide gel electrophoresis and calculated from its amino acid composition, was about 39,000. The molecular weight of this protein, determined by means of high-speed sedimentation equilibrium, ranged between 80,000 and 120,000. Glutamic and asparatic acids, lysine, alanine, and leucine were the predominant amino acids.
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PMID:Characterization of group A streptococcal T-12 protein purified by ion-exchange column chromatography. 36 81

T protein was isolated from Streptococcus pyogenes types 1 and 12 by application CNBr-sepharose-trypsin and purified by ion exchange chromatography. It was indicated that purified T1 and T12 proteins have lymphocyte transforming activity. It was also observed that T12 protein induces immediate and delayed type hypersensitivity in guinea pigs previously sensitized with T12 antigen emulsified with complete FREUND's adjuvant.
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PMID:Streptococcal protein T induced hyperdelayed sensitivity and lymphocyte stimulation. 36 82

Purified Streptomyces albus lytic enzyme was used in an attempt to extract type-specific antigen from a type 1, group A streptococcus. The presumably type-specific antigen was purified by ammonium sulfate fractionation followed by chromatography on O-(carboxymethyl)-cellulose columns. Comparison of the enzyme-extracted substance with acid-extracted material showed it to be serologically different from M protein. In addition, the extract obtained by enzyme treatment was resistant to trypsin as well as to the lytic enzyme. It was inactivated partially by pepsin and totally by papain. Comparison of the enzyme extract with pepsin-extracted T antigen showed these two preparations to be serologically identical. Subtle differences in their susceptibility to heat and acid treatment were noted. Immunodiffusion analyses of acid-extracted M protein and pepsin-extracted T protein, as well as with the enzyme extract, clearly established that the M-protein preparation contained a component serologically identical with one of the precipitinogens common to the other two extracts.
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PMID:Comparison of Streptomyces albus muramidase-extracted streptococcal antigen with acid-extracted M antigen and with pepsin-extracted T antigen. 40 3

A T antigen preparation free of trypsin was obtained by application of CNBr-Sepharose linked to pure trypsin. Purification on an ion exchange chromatography column results in an electrophoretically homogeneous preparation of T protein.
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PMID:T antigen of Streptococcus pyogenes: isolation and purification. 77 30

T protein is a trypsin- and pepsin-resistant molecule on the surface of group A streptococci used as a serological tool to differentiate streptococci of this group. The purpose of this study was to determine the relatedness among the T protein genes of the 25 known T serotypes. DNA probes were constructed which represented various regions of the structural gene for the T6 protein, tee6. The probes were assayed for their ability to hybridize HindIII digests of chromosomal DNA from the 25 different T serotypes. Probe pTEE6.3, coding for the entire T6 protein, and pTEE6(1-299), coding for the amino-terminal half of T6, displayed the highest amount of homology, each binding to 10 of 25 T serotypes. Probes coding for sequences in the carboxy-terminal half of T6 showed considerably less homology among T serotypes with one probe hybridizing with only three out of 25. A synthetic oligonucleotide coding for the carboxy-terminal hydrophobic domain of T6, an area conserved to some degree among several bacterial surface proteins, showed homology with only seven out of 25 T serotypes. Hybridization with sequences outside the tee6 coding area provided additional information on the relatedness of certain sets of T serotypes according to restriction-fragment size heterogeneity. Clearly, there is considerable diversity among T-serotype genes. The data suggest that two or more families of structurally variant T proteins exist, which share only the property of proteolytic resistance and/or, perhaps, some biological function.
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PMID:Genetic diversity among the T-protein genes of group A streptococci. 180 37

The gene for the trypsin-resistant surface T6 protein of Streptococcus pyogenes D471 (M type 6) was cloned and expressed in Escherichia coli. The complete nucleotide sequence of the gene (tee6) and its flanking regions was determined and found to include only one major open reading frame coding for a protein of 537 amino acids (Mr, 57,675). The N terminus of the deduced protein sequence exhibits features of a typical signal sequence, and the C-terminal segment was found to have a high degree of homology with the membrane anchor region of other gram-positive surface proteins, such as streptococcal M protein, wapA protein from Streptococcus mutans and staphylococcal protein A. A hexapeptide having the consensus sequence LPSTGE and located immediately upstream of the C-terminal hydrophobic segment showed the highest degree of conservation at both the protein and DNA levels, with nearly all reported surface proteins from gram-positive cocci. The amino acid composition of the T6 protein revealed 21% serine and threonine residues distributed nearly regularly throughout the molecule, and analysis of the secondary structure predicted a conformation composed of greater than 70% beta-sheet potential interrupted by beta-turns or random coils. Localization experiments in E. coli show very little T6 protein in the periplasmic space. When found here, however, this T6 protein had a molecular mass of 55 kilodaltons, similar to that extracted from the streptococci by nonionic detergent. Most of the T6 protein was found localized in the membrane fraction, where it was composed of a triple band of 60, 58, and 57 kilodaltons. The coexistence of streptococcal surface proteins which are either resistant (T protein) or sensitive (M protein) to proteolytic enzymes may offer a new dimension to the modulation of these antigens under specific biological conditions.
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PMID:Sequence and structural characteristics of the trypsin-resistant T6 surface protein of group A streptococci. 218 57

T-proteins of Streptococcus pyogenes type 1 were extracted by enzymatic treatment of cells with trypsin, pepsin or C-phage-associated lysin and subsequently purified by ion exchange chromatography on DEAE cellulose as well as by immuno-adsorption on immobilized anti-T-type 1 antibodies. Immunochromatographical purified T1-proteins which were extracted by the different enzymes showed different properties in immuno-electrophoresis, SDS-electrophoresis and amino acid composition although a serological reaction of identity was found in Ouchterlony precipitation. Tryptic and peptic digestion was efficient for extraction of T protein while the extraction with C-phage-associated lysin was unsuitable for isolation of T-protein. The release of T-protein after treatment of cells with this lysin was very low and the preparation purified by this way exhibited cross-reaction with non-absorbed antisera of other types.
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PMID:[T-proteins of Streptococcus pyogenes. III. Communication: purification of T-proteins extracted with trypsin, pepsin and C-phage-associated lysin by means of immunochromatography (author's transl)]. 616 40

The DNA of the promoter region of omp T, including the putative start for the pro-Omp T protein (pro-protein a), has been sequenced. Previous studies showed that trypsin inhibitors prevent the processing of pro-Omp T to Omp T protein which led to the prediction that the processing site would be a lysine or an arginine. The deduced amino acid sequence contains a lysine at amino acid 12 and an arginine at amino acid 17 from the N terminus. Chou-Fassman analysis would predict processing at the lysine (but not the arginine) to remove a 1389 dalton peptide, consistent with the fact that the estimated molecular masses of pro-Omp T and Omp T are 42 kd and 40 kd respectively. In addition, the predicted mRNA of the promoter region can form a stable secondary structure (-17.1 kcal) that sequesters the Shine-Dalgarno (SD) sequence as well as the initiator AUG codon. There is evidence that the per A (tpo, envZ) gene product is required for synthesis of Omp T protein (as well as several outer membrane and periplasmic proteins). The perA gene product could be activating translation of Omp T protein by disrupting the mRNA secondary structure that sequesters the SD sequence. Omp T protein synthesis is reduced at temperatures below 32 degrees C and this may also be related to the greater stability of the sequestered SD sequence of the mRNA at low temperature.
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PMID:Sequence of the regulatory region of omp T, the gene specifying major outer membrane protein a (3b) of Escherichia coli K-12: implications for regulation and processing. 632 18

T-protein of Streptococcus pyogenes, type 1 (strain SF 130 Griffith) was extracted by enzymatic treatment of the cells with trypsin and partially purified by ion exchange chromatography on DEAE cellulose and gel chromatography on ultrogel ACA 44. The crude T protein still showing serologically type specific and cross reactions finally was applied to a fibrinogen sepharose column. Components eluted with the neutral buffer (0.05 M phosphate, 0.2 M NaCl, 0.02% NaN3, pH 7.0) reacted serologically in the same manner as the crude T protein. By using 0.1 M citrate, 6 M urea pH 3.0 buffer a type specifically reacting protein (T1-TRYP-F) was eluted from the fibrinogen column. T1-TRYP-F showed identical precipitation lines with the recently characterized T1-protein (T1-TRYP-I) purified by immunochromatography on type specific anti-T antibodies. Comparison of the SDS-patterns of T1-TRYP-F and T1-TRYP-I revealed a less complex molecular size subunit structure for the fibrinogen binding T1-TRYP-F (two bands of 60000 and 70000) as found for T1-TRYP-I, which showed serologically active peptides between 30000 to about 500000. It is discussed that T protein also may be linked covalently with fibrinogen receptors as it has been reported for M protein.
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PMID:[T-proteins of Streptococcus pyogenes. IV. Isolation of T1-protein using affinity chromatography on immobilized fibrinogen]. 644 17

T protein was extracted with trypsin from an avirulent, M protein-deficient, type 1 group A Streptococcus and purified by ammonium sulfate precipitation and anion-exchange chromatography. The latter procedure removed contaminating lipoteichoic acid (LTA) from the T protein, which consisted of a heterogeneous mixture of polypeptides resistant to digestion by trypsin and ranged in molecular size from 160,000 to 200,000 daltons. Threonine, aspartic acid, glutamic acid, lysine, and valine were the most predominant amino acids. The binding of LTA to an affinity column of T protein was reversible with increasing concentrations of ethanol but not with increasing ionic strength. T protein bound less palmitic acid and LTA than did fatty acid-free bovine albumin and did not stimulate human peripheral lymphocytes. Because the surface and cell wall distribution of the T proteins and LTA appear similar, the possibility exists that T proteins and LTA may interact in situ by weakly hydrophobic bonds. Such ligand-ligand interaction may be indirectly involved in the adherence of group A streptococci to host cell membranes that is known to be mediated by LTA.
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PMID:Lipoteichoic acid-binding and biological properties of T protein of group A streptococcus. 701 85


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