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)

Live Ascaris suum females were incubated in medium containing chymotrypsin liganded to fluorescein-5-isothiocyanate, and eggs in the parasite's genital tract took up the probe and fluoresced. Eggs passed by these worms into the medium containing fluorescent probe retained their fluorescence in formaldehyde-saline and by 65 days had developed into second stage infective larvae. Eggs passed naturally by untreated worms were incubated in media containing fluorescent probes and all of the eggs exposed to chymotrypsin liganded to fluorescein-5-isothiocyanate were extensively labeled. Control eggs were labeled sporadically and less intensely, indicating specificity in the uptake of environmental proteins. Chymotrypsin from the parasite's environment can bind to A. suum eggs, and this occurs both inside the worm's genital tract and outside of the parasite. Immunoperoxidase studies showed that IgG developed against chymotrypsin or against A. suum chymotrypsin/elastase isoinhibitors A or C, binds to antigens in cross sections of second stage larvae and their egg shell coats. This suggests that host chymotrypsin is retained during development and may be complexed to A. suum isoinhibitors A and C.
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PMID:Ascaris suum: immunoperoxidase and fluorescent probe analysis of host proteases and parasite proteinase inhibitors in developing eggs and second stage larvae. 308 62

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

Platelet aggregation inducer and inhibitor were isolated from Echis carinatus snake venom. The venom inducer caused aggregation of washed rabbit platelets which could be inhibited completely by heparin or hirudin. The venom inducer also inhibited both the reversibility of platelet aggregation induced by ADP and the disaggregating effect of prostaglandin E1 on the aggregation induced by collagen in the presence of A23187, arachidonate, ADP and platelet-activating factor (PAF) with an IC50 of around 10 micrograms/ml. It did not inhibit the agglutination of formaldehyde-treated platelets induced by polylysine. In the presence of indomethacin or in ADP-refractory platelets or thrombin-degranulated platelets, the venom inhibitor further inhibited the collagen-induced aggregation. Fibrinogen antagonized competitively the inhibitory action of the venom inhibitor in collagen-induced aggregation. In chymotrypsin-treated platelets, the venom inhibitor abolished the aggregation induced by fibrinogen. It was concluded that the venom inducer caused platelet aggregation indirectly by the conversion of prothrombin to thrombin, while the venom inhibitor inhibited platelet aggregation by interfering with the interaction between fibrinogen and platelets.
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PMID:Action mechanism of the platelet aggregation inducer and inhibitor from Echis carinatus snake venom. 392 5

In histological preparations commonly fixed in formaldehyde and embedded in paraffin which on immunofluorescent examination yielded results negative results or but very poor immunofluorescence, prominently positive results were obtained by chymotrypsin treatment on using the method of fluorescent antibodies. Corresponding results were also obtained in cryostat sections fixed for some min up to several days in formaldehyde so that immunofluorescence was completely negative. The positive immunofluorescent results indicate total or partial restoration of antigenicity of tissue proteins previously altered by formaldehyde.
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PMID:Antigenicity restoration of formaldehyde-treated material with chymotrypsin. 616 Jul 17

Fusion of splenic lymphocytes from Lewis rats, immunized with affinity-purified estrogen receptor from the cytosol of MCF-7 human breast cancer cells, with two different mouse myeloma lines, has provided 13 monoclonal hybridoma lines secreting antiestrophilin antibodies, each of which (with one possible exception) recognizes a different antigenic determinant in the human receptor molecule. Of this library of monoclonal antibodies, some react with estrophilin from all sources tested, some react with mammalian but not avian receptors, whereas one preparation appears specific for estrophilin from primate sources. By proteolytic digestion under controlled conditions with mercury-deactivated papain, chymotrypsin, and trypsin, respectively, it is possible to remove sequentially the determinants recognized by one, two or three of the monoclonal antibodies, leaving the epitopes for the six remaining antibodies investigated on the steroid-binding portion of the receptor. The proteolytic fragment containing the epitope most readily removed (by mercuripapain) also contains the DNA-binding domain of the activated receptor molecule. Immunocytochemical staining, using the peroxidase procedure with various monoclonal antibody preparations, of frozen sections of human breast cancer tissue, fixed in ethanol or in picric acid-formaldehyde reagent, shows clearly that the majority of the native receptor, which appears in the cytosol after tissue homogenization, is actually localized within the nuclear compartment in the intact cell. The immunocytochemical technique also permits the identification of mixed populations of receptor-containing and non-containing cells in human breast cancers.
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PMID:Immunochemical studies of estrogen receptors. 620 Jul

Since lysozyme and alpha 1-anti-chymotrypsin are constituents of normal histiocytes, their value as tumor cell markers in histiocytes neoplasias has been investigated using the indirect immunoperoxidase method and commercially available specific antisera on formaldehyde-fixed, paraffin-embedded 5 micrometers sections after pretreatment with pronase. The distribution of both markers was determined in 35 cases of malignant fibrous histiocytoma (MFH) and in 13 cases of malignant histiocytosis (MH). In 12 cases of MH both markers were found whereas in MFH alpha 1-antichymotrypsin was demonstrated in 26 and lysozyme in 16 cases only. In general, the staining for alpha 1-anti-chymotrypsin was more intense than the staining for lysozyme. A negative reaction does not exclude the possibility of MH or MFH. The presence of both constituents in tumours, however, can be considered as indicative of histiocytogenic origin and both can be useful markers for distinguishing histiocytic neoplasias from other tumours.
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PMID:Lysozyme (muramidase) and alpha 1-anti-chymotrypsin as immunohistochemical tumour markers. 628 96

Cellulose and microcrystalline cellulose are treated consecutively with sodium periodate and urea. The interaction of urea derivatives with formaldehyde results in highly reactive groups, capable of further condensation with the amino acid residues of the proteins. The condensation of chymotrypsin, pepsin, and ovomucoid with such activated matrices has been studied in the pH interval 2 to 10. Differences have been found in the binding properties of basic and acid proteins. Satisfactory values have been obtained concerning the relative enzymatic and inhibitory activity of the immobilized products with respect to high- and low-molecular substrates. Chymotrypsin, immobilized on microcrystalline cellulose matrix, is found to manifest better catalytic properties compared with chymotrypsin immobilized on cellulose matrix. A probable sequence of the stages of chemical activation of the matrices and covalent binding of the proteins to them has been proposed. The main advantages of the proposed method consist of the high reactivity of the binding group in a wide pH range, its suitable length, and its easy synthesis.
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PMID:New method for covalent immobilization of proteins to cellulose and cellulose derivatives. 644 11

Antibodies to mastocytes were localized in cells and tissues following formaldehyde or paraformaldehyde fixation and embedding into paraffin or Durcupan ACM, and after chymotrypsin treatment of the sections. Immunomicroscopic examination yielded a more distinct picture of the amount and localization of mastocytes in different tissues.
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PMID:Immunohistochemical identification of mastocytes. 682 Jun 6

The adherence of Candida albicans to a fibrin-platelet matrix formed in vitro was studied. Platelet-rich plasma obtained from rabbits was incubated with thrombin and CaCl2 to form a clot in tissue culture dishes. Such clots were then infected with 3 x 10(7) C. albicans cells per 0.3 ml prelabeled with [U14C]-glucose, and the percent adherence was measured after 30 min of incubation by counting the radioactivity in saline washes of the clot as well as a streptokinase-streptodornase digest of the corresponding clot. Heat- and formaldehyde-killed cells did not adhere as well as viable cells. Pretreatment of C. albicans with trypsin, chymotrypsin, and pronase reduced adherence to the clots. Normal rabbit serum and anti-Candida antiserum also inhibited adherence 40 and 100%, respectively, Diethylaminoethyl-purified anti-Candida gamma globulin (1:8) completely inhibited adherence, whereas purified normal serum gamma globulin did not. Several Candida spp. and Saccharomyces cerevisiae showed differences in their ability to adhere to clots. C. albicans and C. stellatoidea presented the highest adherence, whereas C. krusei, C. guilliermondii, and S. cerevisiae adhered less readily. Other species were intermediate in their ability to adhere.
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PMID:Adherence of Candida albicans to a fibrin-platelet matrix formed in vitro. 699 22

Oral tissues, especially tooth surfaces, are covered with a layer of salivary proteins. Oral bacterial cells that adsorb to salivary components accumulated on the tooth surface are, as a rule, covered with the same components, especially proteins. Thus, it is possible that the salivary proteins covering the bacterial cells are related to the adhesion of bacteria to oral tissues. The aim of this study was to clarify the mechanisms of adsorption of salivary proteins to the surface of Streptococcus sanguis, S. mitis and S. salivarius using an adsorption assay with salivary proteins labeled with tritiated formaldehyde. The results showed that salivary proteins adsorbed more to S. salivarius than to S. mitis, and least to S. sanguis. It was evident that hydrophobic bonding was involved in the adsorption of salivary proteins to the bacterial cells tested. The amount of salivary proteins adsorbed to S. mitis and S. salivarius was decreased by the presence of phosphate, that to S. sanguis was increased by the presence of a divalent cation such as Ca2+, and that to all bacteria tested was inhibited in different ways by the presence of sugars. The amount of salivary proteins adsorbed to S. sanguis and S. salivarius was reduced effectively by pretreatment of the cells with trypsin, chymotrypsin and papain. In the case of S. mitis, the amount of adsorbed salivary proteins was decreased by pretreatment of the cells with chymotrypsin only, and was increased by pretreatment with lipase. These results indicate that there are different mechanisms of adsorption of salivary protein to the cell surfaces of oral streptococci.
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PMID:Adsorption of salivary proteins to the surface of oral streptococcal cells. 786 31


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