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

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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)

In adult rabbits intravenously injected with toxic shock syndrome toxin 1 (TSST-1) or staphylococcal enterotoxin B, serum lectin-like activity (detectable by cation-dependent agglutination of bacteria) developed. This activity was sensitive to heat, trypsin, and formaldehyde but resistant to neuraminidase or galactose oxidase. Formaldehyde-fixed Propionibacterium acnes or Escherichia coli cells reactive with plant lectins provided sensitive targets for titration of serum agglutination activity that was competitively blocked with D-galactose, D-glucose, D-mannose, and alpha-L-fucose. The lectin-like activity, partially purified by affinity chromatography, was a protein of approximately 76,000 Da with an isoelectric point of 5.4. Both lectin-positive and normal serum contained agglutination inhibitors that were absorbed by protein A-producing staphylococci. S protein may be the origin of this lectin-like activity. In vitro exposure of peripheral-blood mononuclear cells to TSST-1 (1.0 micrograms/mL) and to lectin-positive serum induced rapid cell clumping and subsequent "activation" to a larger blast form expressing receptors for buccal epithelial cells. The interaction of toxin/lymphokine-activated mononuclear cells with glycoproteins and/or other antigens selectively expressed by tissues in various organ systems may play a role in target cell pathology in rabbits dying with toxic shock syndrome.
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PMID:Characteristics of toxic shock syndrome toxin 1-induced lectin-like activity and inhibitor(s) in rabbit serum. 292 48

A reaction of the basic amino acids, lysine and arginine, with components of cigarette smoke has been observed. The adducts produced have been identified as cyanomethyl derivatives. Both formaldehyde and cyanide, which are known to be present in cigarette smoke, are involved in the reaction with the primary amino group. The reaction is time-dependent and can be enhanced by an increase of temperature or by incubation under alkaline conditions. Cyanomethyl adduct formation was found to be increased when smoke from cigarettes with higher tar and nicotine content was used. When proteins, such as bovine serum albumin, trypsin inhibitors or crude rat lung proteins were incubated with the cigarette smoke solution, new protein adducts with increased pI values were produced which are separable from the original proteins by gel isoelectric focussing. Radioisotopically labelled cyanide can be irreversibly linked to protein and the linkage is enhanced in the presence of formaldehyde.
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PMID:Formation of cyanomethyl derivatives of basic amino acids and proteins with components in cigarette smoke. 314 35

A fluorescent probe has been employed to study the status of a tumour associated protease, guanidinobenzoatase, in frozen sections of human tumours obtained from the head and neck regions. The results indicate that in vivo a naturally occurring inhibitor of guanidinobenzoatase effectively controls the activity of this enzyme on the majority of cells in a tumour mass. This inhibitor can be artificially displaced by formaldehyde treatment of the frozen sections and this treatment reveals the extent of latent enzyme in the section. In the frozen sections it was noticed that at the advancing edges of the tumour mass, the tumour cells possessed uninhibited guanidinobenzoatase, an enzyme known to degrade the link peptide between cells and fibronectin. It was shown that a synthetic inhibitor of guanidinobenzoatase selectively inhibited the guanidinobenzoatase of the tumour cells at the advancing edge of the tumour mass. It is suggested that the guanidinobenzoatase on cells at the leading edge of the tumour mass plays an important role in the invasion of adjacent host tissue. This synthetic inhibitor of guanidinobenzoatase has no inhibitory action on other trypsin-like enzymes and might therefore be of value in limiting the growth of the tumour mass in vivo.
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PMID:Studies on the activity of a protease associated with cells at the advancing edge of human tumour masses in frozen sections. 316 93

A total of 26 isolates of Actinobacillus pleuropneumoniae were tested for their ability to agglutinate erythrocytes of different origins. Seven different hemagglutination patterns were found. Ten (38%) isolates did not agglutinate any of the erythrocytes tested. The remaining 16 (62%) isolates agglutinated human erythrocytes, and among these, 12 also agglutinated rat, cat, dog, guinea pig, or bovine erythrocytes. No correlation was found between the seven different hemagglutination patterns observed and the serotypes. Hemagglutination activity was destroyed by heating at 100 degrees C as well as by formaldehyde treatment, but was not affected by heating at 60 degrees C, by treatment with trypsin or pronase, or by homogenization of bacterial cells. No fimbriae were observed on examination of bacterial cells negatively stained with phosphotungstate using electron microscopy. Hydrophobic surface properties of the isolates were evaluated. All the isolates appear to possess a hydrophilic cell surface. The present study provides evidence that certain isolates of A. pleuropneumoniae possess hemagglutinating properties which do not appear to be mediated by fimbriae or to involve hydrophobic interactions.
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PMID:Hemagglutinating properties of Actinobacillus pleuropneumoniae. 321 8

Microwave (MW) energy permits rapid tissue fixation for light and electron microscopy but its effects on antigen preservation have not been fully evaluated. We, therefore, fixed three samples of human skin, uterus, and cervix, and two samples of human colon and breast by MW irradiation (5 to 8 seconds) during simultaneous immersion in a dilute aldehyde mixture (2% formaldehyde and 0.05% glutaraldehyde). For comparison, similar portions of each specimen were fixed in formalin. Specimens were processed routinely and embedded in paraffin for light microscopy. Sections from each specimen were stained with hematoxylin and eosin and, by immunoperoxidase techniques, for epithelial membrane antigen, leukocyte common antigen, S-100 keratin, carcinoembryonic antigen, and factor VIII-related antigen, the latter three with and without preliminary trypsinization. Colon sections were also stained for chromogranin. In all cases, light microscopic morphology was comparable for tissues fixed by the MW method and formalin-fixed specimens, as was immunostaining for epithelial membrane antigen, leukocyte common antigen, S-100 protein, and chromogranin. Formalin-fixed tissues required trypsinization for optimal detection of keratin, carcinoembryonic antigen, and factor VIII-related antigen. In contrast, trypsin-pretreatment was not necessary to demonstrate these antigens in MW-fixed specimens and, in fact, resulted in tissue digestion. We conclude that this MW fixation method provides a means for rapidly fixing tissues for immunoperoxidase staining while preserving excellent light microscopic morphology.
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PMID:Rapid microwave fixation of human tissues for light microscopic immunoperoxidase identification of diagnostically useful antigens. 331 39

The present study is an immunohistochemical analysis utilizing a series of mono- and polyclonal antibodies to myoglobin, desmin and vimentin in smooth and striated control muscle tissues, 7 alveolar and 7 embryonal rhabdomyosarcomas and 1 adult and 1 fetal rhabdomyoma with ultrastructurally proven rhabdomyoblastic differentiation in all the tumors. Formaldehyde-fixed and paraffin-embedded tissue was used for the immunohistochemical analysis of all the tumors, while ethanol fixation was also used for the analysis of the control tissues. The staining for myoglobin with the poly- and monoclonal antibody used was positive in both formaldehyde- and ethanol-fixed skeletal and cardiac control muscle. Trypsin treatment abolished the positive staining when the monoclonal antibody was used. Both the striated and smooth control muscle tissues were positively stained by the antidesmin antibodies. The influence of the fixative that was used and the trypsin treatment depended on the antibody used and the type and origin of the muscle tissue. All the tumors were positively stained with the polyclonal antimyoglobin and 8/14 rhabdomyosarcomas and the 2 rhabdomyomas were positively stained with the monoclonal antimyoglobin. All the tumors were positively stained with the polyclonal and 3 of the 5 monoclonal antidesmin antibodies used. Well-differentiated tumor cells were usually positively stained for both myoglobin and desmin. There were small, poorly differentiated tumor cells in the rhabdomyosarcomas and the fetal rhabdomyoma which were positively stained for desmin, whereas very few or no such cells were positively stained for myoglobin. A varying number of mostly small, poorly differentiated tumor cells were positively stained for vimentin in 12 of 14 rhabdomyosarcomas and in the fetal rhabdomyoma. The study showed that one of the monoclonal antidesmin antibodies produced the most consistent result with a positive staining in all cases. The monoclonal antimyoglobin antibody, which is a specific marker of rhabdomyoblastic differentiation, is also considered to be of value, although it did not produce positivity in all cases. It remains to be shown whether desmin can help in the diagnosis of poorly or undifferentiated rhabdomyosarcomas without light- or electron-microscopic evidence of rhabdomyoblastic differentiation.
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PMID:Myoglobin, desmin and vimentin in ultrastructurally proven rhabdomyomas and rhabdomyosarcomas. An immunohistochemical study utilizing a series of monoclonal and polyclonal antibodies. 368 91

Androgen receptor-acceptor complexes in nuclei from rat ventral prostates were cross-linked in situ with formaldehyde and partially purified using affinity chromatography. To isolate acceptor DNA, the cross-linked receptor-acceptor complexes in formaldehyde-treated chromatin samples were adsorbed to dihydrotestosterone-17 beta-succinyl agarose, eluted with 75 microM dihydrotestosterone-1% SDS, digested with proteinase K and extracted with phenol-chloroform. After 32P end-labelling and PAGE, this DNA contained two distinct bands of DNA (about 300 and 400 base pairs respectively) which were unique relative to the total prostatic DNA. As an alternative approach for characterizing acceptor DNA, the DNA in prostatic nuclei and cross-linked chromatin was labelled with 32P by nick translation and analysed in glycerol density gradients for associations with cross-linked androgen receptors. A symmetrical 7s peak of 32P-DNA with a small amount of coincident receptor was observed in the gradients after mild trypsin treatment. In the absence of trypsin treatment, both the cross-linked receptors and the labelled DNA sedimented to the bottom of the gradients. Isolation of acceptor proteins involved iodination of cross-linked chromatin with 125I and androgen affinity chromatography. A comparison of the relative efficiency of retention and elution of 125I-proteins from different affinity columns revealed that testosterone-17 beta-succinyl agarose was potentially most suitable for purification of acceptor proteins. After electrophoresis on SDS-polyacrylamide gels, the eluates from this type of affinity matrix were found to contain two major peaks of 125I-labelled proteins--one corresponding to a protein with a similar molecular weight as the nuclear androgen receptor (33,000 Da); the other having a molecular weight of 20,000 Da. While the precise identity of this latter entity is unknown, its enrichment and retention by the affinity gel implies that it is closely associated with the androgen receptor and may be a component of the acceptor sites.
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PMID:DNA and protein components of nuclear acceptor sites for androgen receptors in the rat prostate. 369 93

Staphylococcus aureus can bind soluble collagen in a specific, saturable manner. We have previously shown that some variability exists in the degree of collagen binding between different strains of heat-killed, formaldehyde-fixed S. aureus which are commercially available as immunologic reagents. The present study demonstrates that live S. aureus of the Cowan 1 strain binds amounts of collagen per organism equivalent to those demonstrated previously in heat-killed, formaldehyde-fixed bacteria but has an affinity over 100 times greater, with Kd values of 9.7 X 10(-11) M and 4.3 X 10(-8) M for live and heat-killed organisms, respectively. Studies were also carried out with S. aureus killed by ionizing radiation, since this method of killing the organism seemed less likely to alter the binding moieties on the surface than did heat killing. Bacteria killed by exposure to gamma radiation bound collagen in a manner essentially indistinguishable from that of live organisms. Binding of collagen to irradiated cells of the Cowan 1 strain was rapid, with equilibrium reached by 30 min at 22 degrees C, and was fully reversible. The binding was not inhibited by fibronectin, fibrinogen, C1q, or immunoglobulin G, suggesting a binding site for collagen distinct from those for these proteins. Collagen binding was virtually eliminated in trypsin-treated organisms, indicating that the binding site has a protein component. Of four strains examined, Cowan 1 and S. aureus ATCC 25923 showed saturable, specific binding, while strains Woods and S4 showed a complete lack of binding. These results suggest that some strains of S. aureus contain high-affinity binding sites for collagen. While the number of binding sites per bacterium varied sixfold in the two collagen-binding strains, the apparent affinity was similar. The ability of S. aureus to bind collagen with high affinity may provide a mechanism for bacterial adhesion to host tissue and thereby play a role in the invasive characteristics of this organism.
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PMID:Collagen binding to Staphylococcus aureus. 377 Sep 47

Limited proteolysis and chemical cross-linking techniques have been used to study the interaction between alpha- and beta-tubulin subunits. Trypsin digestion of tubulin dimer resulted in the cleavage of the alpha-subunit into two fragments, whereas chymotrypsin cleaved the beta-subunit into two distinct fragments. All of these fragments have been mapped on the tubulin subunits by further proteolysis with formic acid. Cross-linking of trypsin- and chymotrypsin-cleaved subunits has been performed with two different cross-linker agents of different cross-linking distance. The addition of formaldehyde resulted in the cross-linking of the alpha-tubulin N-terminal fragment with beta-tubulin C-terminal domain. The same result was obtained when methyl 4-mercaptobutyrimidate was used.
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PMID:The interaction between subunits in the tubulin dimer. 390 10

A new hypothesis is proposed on the involvement of nucleosomes in Giemsa banding of chromosomes. Giemsa staining as well as the concomitant swelling can be explained as an insertion of the triple charged hydrophobic dye complex between the negatively-charged super-coiled helical DNA and the denatured histone cores of the nucleosomes still present in the fixed chromosomes. New cytochemical data and recent results from biochemical literature on nucleosomes are presented in support of this hypothesis. Chromosomes are stained by the Giemsa procedure in a purple (magenta) colour. Giemsa staining of DNA and histone (isolated or in a simple mixture) in model experiments results in different colours, indicating that a higher order configuration of these chromosomal components lies at the basis of the Giemsa method. Cytophotometry of Giemsa dye absorbance of chromosomes shows that the banding in the case of saline pretreatment is due to a relative absence of the complex in the faintly coloured bands (interbands). Pretreatment with trypsin results in an increase in Giemsa dye uptake in the stained bands. Cytophotometric measurements of free phosphate groups before and after pretreatment with saline, reveal a blocking of about half of the free phosphate groups indicating that a substantial number of free amino groups is still present in the fixed chromosomes. Glutaraldehyde treatment inhibited Giemsa-banding irreversibly while the formaldehyde-induced disappearance of the bands could be restored by a washing procedure. These results correlate with those of biochemical nucleosome studies using the same aldehydes. Based on these findings and on the known properties of nucleosomes, a mechanism is proposed that explains the collapse of the chromosome structure when fixed chromosomes are transferred to aqueous buffer solutions. During homogeneous Giemsa staining reswelling of the unpretreated chromosome is explained by insertion of the hydrophobic Giemsa complex between the hydrophobic nucleosome cores and the superhelix DNA. Selective Giemsa staining of the AT-enriched bands after saline pretreatment is thought to be due to the, biochemically well-documented, higher affinity of arginine-rich proteins present in the core histones for GC-enriched DNA, which prevents the insertion of the Giemsa complex in the interbands. Production of Giemsa bands by trypsin pretreatment can be related to the action of this enzyme on the H1 histones and subsequent charge rearrangements.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The involvement of nucleosomes in Giemsa staining of chromosomes. A new hypothesis on the banding mechanism. 392 63


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