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)

Studies of the Fc receptor induced by herpes simplex virus using the 7S EA rosette assay reveal that (i) the percentage of cells showing receptor activity is multiplicity-dependent; (ii) the percentage of cells rosetting is independent is independent of the cell cycle phase of the host cell; (iii) RNA and viral protein synthesis, and probably glycosidation, are required for the induction of the receptor but not viral DNA synthesis; and (iv) the receptor is neuraminidase-resistant but trypsin-sensitive.
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PMID:Characteristics of the Fc receptor induced by herpes simplex virus. 7 67

Cell cultures originated from human foreskin (HFS) tissues were used for isolation of viruses from diagnostic specimens. The foreskins were collected in Hank's balanced salt solution and then processed on the same day by dispersion in trypsin. A week after the trypsin treatment of the tissues, the first cell cultures were ready to use. Continuous subcultures in vitro of the cells gave rise to a colony of cells that multiplied freely in vitro and supported the growth of viruses from the herpes group. In three cases tested in our laboratory in the last 6 months, viruses from the herpes group were isolated on the HES. The cytopathic changes of the HFS cells were observed 5 to 8 days after infection. They were not detected on two other human-origin cell cultures (WI-38 and HEp2) or on primary monkey kidney cells. The viruses isolated from these three cases were cytomegalovirus (CMV) from urine of a 2-week-old baby, a second CMV from a cutaneous lesion of a renal-transplant patient and herpes simplex virus from the eye swab of a young girl. After a few subcultures on the HFS cells, the three viruses produced CPE on the other susceptible human cells. The preparation of HFS cells is easy, the availability of the tissue is high, and the diagnostic value is unquestionable. It is suggested that this tissue and its cell cultures be used more often in diagnostic and research laboratories.
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PMID:The use of human foreskin cell cultures for isolation of herpesvirus group in the diagnostic laboratory. 18 Jul 93

Human cytomegalovirus (CMV) was inactivated by treatment with phytohemagglutinin (PHA) in contrast to herpes simplex virus (HSV), which was not. Approximately 90% of infectivity was lost following exposure of CMV to PHA. Greater reduction of infectivity, more than 99%, was obtained following pretreatment of cells with PHA than by direct mixture of the virus and the lectin. Protection of cells was still observed 48 hours after pretreatment of cells with PHA. No difference was found in sensitivity to PHA with 3 strains of CMV tested. PHA preparations from different sources were almost equally effective in inactivation of CMV, whereas leucoagglutinin had minimal effect. Our data suggest that the site of action of PHA occurs at the step(s) of penetration and/or uncoating. Resistance of CMV to trypsin was confirmed, and the enzyme had no effect on sensitivity to lectins.
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PMID:Inactivation of human cytomegalovirus by phytohemagglutinin. 20 93

This study was undertaken to determine if direct cytotoxicity (DC) against herpes simplex virus infected cells, perhaps mediated by T cells, could be demonstrated in individuals subject to recurrent herpes labialis. The mononuclear cells from 7 out of 17 individuals with recurrent herpes expressed DC whereas no DC was ever exhibited by 7 individuals without a previous history of herpes infections. Several approaches were used to show that the cytotoxicity being detected was predominately of the direct type rather than antibody-dependent cell cytotoxicity (ADCC). Since the effector cells of the DC were sensitive to trypsin treatment and behaved as do natural killer (NK) cells upon cell fractionation, the results were taken to imply that the DC was attributable to a NK-effector cell type rather than a classical T lymphocyte.
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PMID:Direct lymphocytotoxicity against herpes simplex virus infected cells. 21 80

The staining of viral antigens present in formalin-fixed, paraffin-embedded tissues by fluorescent antibodies is markedly enhanced by trypsin digestion. When the trypsin digestion method was used to detect viral antigens present in hamster brain following experimental infection with measles virus, the results were comparable to those obtained with acetone-fixed, freshly frozen tissues that had been sectioned with a cryostat. Measles antigens were readily identified in brain cells from a patient with subacute sclerosing panencephalitis and in lung and liver tissue from a patient with acute giant cell pneumonia, following preparation of the tissues for routine histologic examination. Viral antigens were detected in brain tissue that had been taken from patients with herpes simplex encephalitis and stored in paraffin for up to 15 years. Cells containing antigen could be precisely identified without loss of histologic detail by restaining the same tissue sections with hematoxylin and eosin.
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PMID:Enhancement of fluorescent antibody staining of viral antigens in formalin-fixed tissues by trypsin digestion. 23 Oct 70

Surface antigens induced by herpes simplex virus infection in HeLa cells remain unaltered after treatment of the cells with 2% formalin for 10 min or with 0.08% trypsin for 15 min at 37 degrees C. A longer trypsin treatment (for 1 hour) will cause gradual alterations in the virus-induced antigens. Hence, these antigens are proteins deeply implanted within the cellular membrane. Their mobility--optimal at 37 degrees C--allows aggregation of the antigens in the form of caps or patches by polyvalent ligands such as IgG.
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PMID:Study of cell surface antigens induced by herpes simplex virus. Note II. Some properties of the antigens. 23 59

Radioiodinated normal rabbit IgG was used to detect Fc receptors on the surface of HeLa S3-2 cells infected with herpes simplex virus (HSV). Unlike the Fc receptors present on most leukocytes, these virus-induced Fc receptors were found to be sensitivite to trypsin at concentrations of enzyme as low as 0.1 mg/ml. Treatment of infected cells with neuraminidase enhanced the binding of IgG. Yet the HSV-induced Fc receptor(s) is probably a glycoprotein because its synthesis was inhibited by 2-deoxy-D-glucose at concentrations inhibiting glycoproteins but not total proteins. Binding of radioiodinated IgG to Fc receptors on infected HeLa S3-2 cells was unaffected by F(ab')2 fragments prepared from antisera against uninfected HeLa S3-2 cells or against human beta2-microglobulin. By contrast, anti-HSV F(ab')2 or Fab' fragments decreased binding of radioiodinated IgG to HSV-infected cells by 85%, and binding of radioiodinated Fc was also inhibited by anti-HSV Fab'.
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PMID:Fc receptors induced by herpes simplex virus. I. Biologic and biochemical properties. 68 55

Varicella-zoster virus (VZV) open reading frame (ORF) 62 potentially encodes a protein with considerable amino acid homology to the herpes simplex virus (HSV) immediate-early regulatory polypeptide ICP4 (or IE3). To identify and characterize its protein product(s) (IE62), we used a rabbit antiserum prepared against a synthetic peptide corresponding to the C-terminal 13 amino acids of the predicted protein. This antiserum reacted with phosphorylated polypeptides of 175 to 180 kDa that were made in VZV-infected cells and in cells infected with a vaccinia virus recombinant expressing IE62, but not in control-infected cells, confirming its specificity and reactivity to the IE62 protein. The antiserum recognized a 175-kDa polypeptide in purified virions that comigrated with a major structural protein. Comparison of this reactivity with that of an antipeptide antiserum directed against the VZV ORF 10 product (homologous to the HSV major structural protein VP16) indicates similar levels of ORF 62 and ORF 10 polypeptides in VZV virions. In contrast, antipeptide antiserum directed against the VZV ORF 29 product, the homolog of the HSV major DNA-binding protein, failed to recognize any protein in our virion preparations. Treatment of virions with detergents that disrupt the virion envelope did not dissociate IE62 from the nucleocapsid-tegument structure of the virion. Differential sensitivity of VZV virion IE62 to trypsin digestion in the presence or absence of Triton X-100 indicates that IE62 is protected from trypsin degradation by the virus envelope; since it is not a nucleocapsid protein, we conclude that it is part of the tegument. Finally, we show that the virion 175-kDa protein either can autophosphorylate or is a major substrate in vitro for virion-associated protein kinase activity.
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PMID:The varicella-zoster virus immediate-early protein IE62 is a major component of virus particles. 130 52

Using purified bacterially expressed herpes simplex virus type 1 ribonucleotide reductase large subunit (R1) and the proteolytic enzymes chymotrypsin and trypsin, we have generated stable N-terminal truncations. Chymotrypsin removes 246 amino acids from the amino terminus to produce a fragment (dN246R1) which retains full enzymic activity and affinity for the small subunit (R2). Treatment of R1 with trypsin produces a 120K protein and a cleavage at amino acid residue 305 to produce a fragment (dN305R1) which remains associated with a 33K N-terminal polypeptide. Although this 33K-dN305R1 complex retains full binding affinity for R2 its reductase activity is reduced by approximately 50%. Increasing the concentration of trypsin removes the 33K N-terminal polypeptide resulting in dN305R1 which, when bound to R2, has full ribonucleotide reductase activity. Like R1, dN246R1 and dN305R1 each exist as dimers showing that the first 305 amino acids of R1 are not necessary for dimer formation. These results indicate that, in structural studies of subunit interaction, dN246R1 or dN305R1 can be considered as suitable replacements for intact R1.
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PMID:The unique N terminus of the herpes simplex virus type 1 large subunit is not required for ribonucleotide reductase activity. 130 56

Recent studies have shown that ICP4, one of the major immediate-early proteins of herpes simplex virus type 1 is present within the tegument region of the virion (F. Yao and R. J. Courtney, J. Virol. 63:3338-3344, 1989). With monoclonal antibodies to two additional immediate-early proteins, ICP0 and ICP27, and Western blot (immunoblot) analysis, ICP0, but not ICP27, was also found to be associated with purified virus particles. In an effort to localize the ICP0 within the virion, purified virions were treated with trypsin in the presence and absence of detergent. The data suggest that ICP0 is located within the tegument region of the virion and is not localized in the envelope or within the nucleocapsid. The number of molecules of ICP0 per virion was estimated to be approximately 150.
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PMID:Association of ICP0 but not ICP27 with purified virions of herpes simplex virus type 1. 131 96


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