Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The production of histamine-releasing factor (HRF) by human mononuclear cells has previously been reported. In this paper we describe the production of HRF by guinea pig spleen cells, thymocytes, and PBMC. Guinea pig lymphoid cells were cultured either alone or in the presence of mitogens (PHA and Con A) or specific Ag(OVA and keyhole limpet hemocyanin) and the dialyzed cell-free supernatant was tested for histamine-releasing activity on guinea pig lung mast cells and blood basophils. Lung mast cells were isolated by enzymatic digestion and partially purified by countercurrent elutriation and discontinuous Percoll gradient centrifugation. Guinea pig spleen cells, thymocytes, and PBMC spontaneously produced significant amounts of HRF. The production was enhanced upon stimulation with PHA or specific Ag in animals immunized with Ag in CFA. Two distinct species of HRF were identified with m.w. of 50,000 to 70,000 and 5000 to 8000 by gel chromatography. HRF is a trypsin- and chymotrypsin-sensitive heat-stable protein. It does not bind to Con A-Sepharose and its production is not inhibited by tunicamycin. HRF-induced histamine release from lung mast cells is a temperature-dependent process and is complete in 10 min at 37 degrees C. Intradermal injection of HRF caused an immediate ear-swelling reaction in guinea pigs. The most severe ear-swelling reactions did not resolve within 1 h, but instead evolved over a period of 12 to 24 h.
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PMID:Production and properties of histamine-releasing factor of guinea pigs. 245 Jan 35

A new trypsin-like serine protease was cloned from both a murine cytotoxic T lymphocyte and a human PHA-stimulated peripheral blood lymphocyte cDNA library. In both the mouse and human system, this transcript had a T cell- and NK-specific distribution, being detected in cytotoxic T lymphocytes (CTL), some T-helper clones, and NK, but not in a variety of normal tissues. T-cell activation with Con A plus IL-2 induced mouse spleen cells to express this gene with kinetics correlating with the acquisition of cytolytic capacity. Both the mouse and human nucleotide sequences of this gene encoded an amino acid sequence with 25-40% identity to members of the serine protease family. The active-site "charge-relay" residues (His-57, Asp-102, and Ser-195 of the chymotrypsin numbering system) are conserved, as well as the trypsin-specific Asp (position 189 in trypsin). We reviewed the evidence of this serine protease's role in lymphocyte lysis and proposed a "lytic cascade." We discussed the biological and clinical implications of a cascade, proposing these enzymes as markers for cytolytic cells and as targets for rational drug therapy. Genetic and acquired deficits in the lethal hit-delivery system are considered as a basis for approaching some immunodeficiency states, including severe EBV infections, T-gamma leukemias, and T8+ lymphocytosis syndromes.
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PMID:A T cell- and natural killer cell-specific, trypsin-like serine protease. Implications of a cytolytic cascade. 305 12

Supernatants from 24 hr cultures of PHA-pulsed human T lymphocytes inhibit the migration of human peripheral blood T lymphocytes and guinea pig macrophages in vitro. The factor responsible for the inhibition of T lymphocytes provisionally called TIF (T cell migration inhibitory factor) was separated from MIF by preparative PAGE, had apparent molecular weight (m.w.) of 1,000-10,000 daltons and isoelectric point of 3.1. TIF activity was resistant to treatment with trypsin, chymotrypsin and neuraminidase but sensitive to PMSF (phenyl-methyl-sulfonyl-fluoride). This suggests that TIF is presumably different from human MIF and may represent a novel lymphokine which preferentially affects T cell migration in vitro.
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PMID:Partial purification and physicochemical properties of human T cell migration inhibitory factor (TIF). 639 62

Digestion of bovine erythrocytes (BE) with trypsin (Tr) or chymotrypsin (CTr) revealed 'Tr and CTr specific' receptors respectively. These receptors reacted with all the isologous, including the autologous, sera. The titres of agglutinability varied for the Tr-digested BE from 1:2 to 1:64 and from zero to 1:128 for the CTr-digested BE. However, the variation between the members of monozygous twin pairs (MZ) in no case exceeded +/- 2 score units, the error limits. Agglutination of the CTr-digested BE gave with the PHA lectin very similar, (r = 0.964) results to that which was obtained with the isologous sera. The titre of agglutinins showed concordance in all the sera of MZ pairs when tested against the neuraminidase-digested human erythrocytes and the Tr or CTr-digested BE. Their variance due to differences varied between MZ pairs from 60.4 to 74.3%.
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PMID:Natural agglutinins to hidden membrane components in the bovine erythrocytes. 689 9

Vicilins (7S storage proteins) from cowpea (Vigna unguiculata) and other legume seeds were shown to bind to chitin, to regenerated chitin (fully acetylated chitin) and to chitosan (deacetylated chitin). Adsorbed vicilins were desorbed from these matrices by acetic and hydrochloric acids and by highly polymerized soluble chitosan. Proteins such as the lectin of common bean (PHA), soybean trypsin inhibitor (Kunitz), a beta-1,3-glucanase from cowpea seeds, bovine pancreatic alpha-chymotrypsin, chicken ovalbumin, serum albumin and rabbit gamma-globulin did not bind. The present result is the first description of vicilin binding to chitin but other proteins, such as wheat germ agglutinin (WGA), a lectin that contains the so called "chitin-binding domain", and a chitinase isolated from cowpea seeds, which are involved in the defense mechanisms of plants against insects and fungi, were also shown to bind to chitin as previously reported. The binding of vicilins to chitin is probably effected not through a "chitin-binding domain" because they do not share this sequence with the defense-related proteins cited above. We propose that this association of vicilins with chitin may be related to the effect of variant vicilins on the development of Callosobruchus maculatus (bruchid) in resistant cowpea seeds.
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PMID:Chitin-binding proteins from cowpea (Vigna unguiculata) seeds. 873 24