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)

Elastolytic enzyme was purified and crystallized from culture fluid of Flavobacterium immotum No. 9-35. The purified enzyme was homogeneous on polyacrylamide gel electrophoresis. The molecular weight was determined by Sephadex G-100 gel filtration to be 13,000. The isoelectric point was between pH 8.3 and 8.9. The optimum pH of the enzyme was 7.2 for elastolytic activity. The purified enzyme showed not only elastolytic activity, but also non-specific proteolytic activity against various other proteins. Milk-clotting activity was also observed. The enzyme did not act on keratin, collagen, or fourteen amino acid esters, including N-benzoyl-L-alanine methyl ester, N-benzoyl-L-arginine ethyl ester, and N-acetyl-L-tyrosine ethyl ester, which were typical substrates of pancreatic elastase [EC 3.4.21.11], trypsin [EC 3.4.21.4], and chymotrypsin [EC 3.4.21.1], respectively. However, the enzyme selectively hydrolyzed elastin when both elastin and albumin were present in the reaction mixture. The enzyme was inhibited by o-phenanthroline and various heavy metals such as cadmium, lead, zinc, and mercury. Various inhibitors, such as diisopropyl phosphofluoridate, tosyl-L-lysine chloromethyl ketone, tosyl-L-phenylalanine chloromethyl ketone, trypsin inhibitor, iodoacetamide, etc., had no effect on the elastolytic activity.
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PMID:Purification and properties of elastolytic enzyme from Flavobacterium immotum. 23 95

The method described below combines an immunoreaction with Papanicolaou's stain on cytological smears. For the immunoreaction, the avidin-biotin-complex (ABC) method was used. The method was tested on various cytological material with the monoclonal antibody lu-5 and two polyclonal antibodies (anti-keratin and anti-chymotrypsin). Wet fixation of the smears with a modified Delaunay's solution is recommended. Drying of the material impairs immunoreactivity. The main advantages of the technique are the clear-cut permanent immunostaining and the preservation of the nuclear structure, permitting a combined immuncytological characterization of cellular products and conventional cyto-diagnosis.
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PMID:Combined immunoreaction and Papanicolaou's stain on cytological smears. 242 37

The cellular sediments of 42 malignant and 16 benign effusions (58 cases) were studied using the immunoperoxidase technique. Serial sections of formalin-fixed, paraffin-embedded residual sediments of effusions, sent for routine cytologic examination, were studied by commercially available polyclonal antisera against lysozyme, alpha 1-anti-trypsin, alpha 1-anti-chymotrypsin, tissue polypeptide antigen (TPA), a wide-spectrum anti-keratin, carcinoembryonic antigen (CEA) and, in single cases, thyroglobulin and prostate-specific antigen. A final definite diagnosis from histologic study of biopsy or autopsy specimens was known in all cases. All carcinomas, the mesotheliomas and the reactive mesothelial cells showed a positive reaction for TPA and, partly, the wide-spectrum keratin. Lysozyme could be demonstrated in the cells of the one proven malignant fibrous histiocytoma; all malignant epithelial cells were negative. Alpha 1-anti-chymotrypsin and alpha 1-anti-trypsin showed similar reactions: they were often positive in carcinoma cells of the breast, the bronchial system and the pancreas, in contrast to a mostly negative reaction in carcinomas of the stomach and ovary. CEA showed considerable differences; it was always negative in benign and malignant mesothelial proliferations but mostly positive in carcinomas of the stomach, pancreas and bronchial system. It was only positive in less than 20% of the carcinomas of the breast and always negative in the proven malignant effusions of primary carcinomas of the ovary and prostate. Studying a combination of several tumor markers is possible in serial paraffin-embedded sections and may be a valuable criterion in the cytologic diagnosis of effusions.
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PMID:Immunohistochemical study of lysozyme, alpha 1-anti-chymotrypsin, tissue polypeptide antigen, keratin and carcinoembryonic antigen in effusion sediments. 243 1

Dermal keratin bodies, consisting mainly of keratin intermediate filament aggregates (KIFA) coated with IgM anti-KIF autoantibodies, are present in normal human skin and occur in increased quantities in certain skin diseases. Keratin bodies are normally rapidly removed, but in primary localized cutaneous amyloidosis (PLCA) they are converted by an unknown mechanism to amyloid. Amyloid P component (AP), a glycoprotein identical to, and derived from, the normal plasma protein serum amyloid P component (SAP), is present in all forms of amyloid including PLCA. We investigated the interaction between SAP, keratin bodies, and KIFA. Immunofluorescence staining of normal skin using fluoresceinated anti-SAP and rhodamine-conjugated anti-IgM, or AE-1/AE-3 anti-keratin antibodies followed by Texas Red-conjugated anti-mouse immunoglobulin, showed that 52% +/- 4 (mean +/- sem, n = 6) of keratin bodies bound anti-SAP. Similar findings were present in a biopsy from a patient with lichen planus. Isolated KIFA, prepared by 8M urea extraction of normal human epidermis or cultured keratinocytes, were preincubated with normal human serum as a source of SAP and then stained with fluoresceinated anti-SAP. Bright fluorescence seen when the incubation medium contained Ca++ was absent in the presence of ethylenediamine tetraacetic acid. Specific Ca++-dependent binding of SAP to KIFA was confirmed using immunoblotting. Binding of SAP to KIFA did not prevent their degradation following exposure to trypsin or alpha-chymotrypsin. Similarly, partial enzymatic digestion of KIFA did not abrogate their ability to bind SAP. Our findings, that SAP is associated with keratin bodies in skin and exhibits Ca++-dependent binding to KIFA in vitro, identify keratin filaments as a newly recognized ligand for SAP.
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PMID:Amyloid P component binds to keratin bodies in human skin and to isolated keratin filament aggregates in vitro. 245 1

Cod Gadus morhua and bovine trypsin degraded human epidermal keratin with similar efficacies in vitro around optimal pH, which was at pH 8.4 for cod trypsin and at pH 9.5 for bovine trypsin. Extract of intestines of cod, Atlantic herring Clupea harengus, Atlantic salmon Salmo salar, and redfish Sebastes marinus degraded keratin with similar efficacies with pH optima between 8.5 and 9.5. Sheets of plantar callus were degraded with somewhat lower efficacy than keratin. The keratin-degrading activity of extract of cod intestines had a temperature optimum around 45 degrees C. Inhibition with benzamidine and 4-phenylbutylamine showed that trypsin amounted to more than 2/3 of the keratin-degrading activity in all extracts of fish intestines. Apart from cod intestines, which had the lowest chymotrypsin content, chymotrypsin made a smaller but significant contribution to the keratin-degrading activity. The present investigation demonstrates that fish trypsin and extract of fish intestines are effective in degrading human epidermal keratin in vitro, and in a recent investigation the same was shown with fish pepsin. This may suggest a possible mechanism for the development of irritative contact eczema caused by exposure to fish.
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PMID:Degradation of human epidermal keratin by cod trypsin and extracts of fish intestines. 246 41

A keratinolytic proteinase with enzyme activity at acidic pH was isolated from culture filtrates of Trichophyton mentagrophytes, a major pathogenic fungus of dermatophytosis. The molecular weight of the proteinase was estimated to be 41,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 38,000 by gel filtration. The isoelectric point was determined to be 3.9. The proteinase had a pH optimum of 4.5 for keratin and 5.5 for hemoglobin. This enzyme hydrolyzed the synthetic chymotrypsin substrate Suc-Ala-Ala-Pro-Phe-MCA (Km, 0.59 mM), and its activity was strongly inhibited by chymostatin. Previously reported proteinases from dermatophytes have had enzyme activities in neutral or alkaline pH; however, healthy skin has a weakly acidic pH. Thus, the purified proteinase which has an optimal activity at acidic pH and hydrolyzes skin constituents could be an important virulence factor in dermatophytosis.
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PMID:Isolation of a keratinolytic proteinase from Trichophyton mentagrophytes with enzymatic activity at acidic pH. 247 74

In order to gain insight into the metabolism of keratin intermediate filaments (KIF) as well as the ability of KIF degradation products to interact with the immune system, we performed enzymatic degradation of purified KIF and examined their interaction with anti-KIF autoantibodies and their ability to act as immunogens. Aliquots of KIF aggregates were exposed to 3 different enzymes, that is, alpha-chymotrypsin, plasmin, and trypsin, in dose- and time-dependent experiments. The effect of the digestion was monitored sequentially by polyacrylamide gel electrophoresis and simultaneously by transmission electron microscopy. Furthermore, the KIF degradation proteins were then examined for their ability to bind anti-KIF autoantibodies by immunoblot and for their immunogenicity. In addition, preincubation of KIF with anti-KIF autoantibodies prior to the digestion procedure was performed to investigate a possible protective effect of this treatment against proteolytic degradation. The experiments demonstrated that: (1) KIF are degraded by serine proteinases, (2) with prolonged incubation time intact KIF are progressively replaced by more granular-amorphous material in transmission electron microscopy, (3) anti-KIF autoantibodies bind to KIF degradation proteins, (4) preincubation of KIF with anti-KIF autoantibodies does not exert any major protective effect for KIF against proteolytic degradation, and (5) the enzymatic degradation products of KIF can function as effective immunogens causing the formation of high-titer anti-KIF antibodies.
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PMID:Immunologic properties of enzymatically degraded human keratin intermediate filaments. 257 28

Affinity-purified antibodies raised against three flagellar tektins (tektin A, B, and C) from each of two sea urchin species (Lytechinus pictus and Strongylocentrotus purpuratus) were used to study the immunological relationship between tektins and intermediate filament proteins. By immunofluorescence microscopy, several antitektins revealed a staining of intermediate filament-like arrays in three vertebrate cell lines tested. Immunoelectron microscopy substantiated the cross reaction of antitektins with intermediate filaments. When the cells were treated with cytochalasin B, the arrangement of the filaments recognized by anti-(Lp)-tektin B was altered; the alteration observed is typical for keratin filaments. By immunoblot, it was found that anti-(Lp)-tektin B cross reacted with two isoforms or different proteins of approximately 54 kD with pIs of 6.1 and 6.2 in human carcinoma epithelia (HeLa) cells and with two isoforms or different proteins of approximately 55 kD with pIs of 6.1 and 6.3 in pig kidney epithelia (LLC-PK1) cells. Furthermore, when antitektin antibodies were affinity purified with the 54 kD HeLa keratin, these keratin-specific antibodies again restained the original tektins on immunoblots. From these observations, it can be concluded that tektins and keratins are to a certain extent immunologically related. To determine the degree of the immunological relationship, tektin filaments and purified intermediate filaments from HeLa cells were cleaved with alpha-chymotrypsin and examined by quantitative immunoblot analysis. On immunoblots of digested tektins from L. pictus, anti-(Lp)-tektin B recognized several cleavage products in the range of 20 kD to 46 kD. However, when immunoblots of digested intermediate filaments from HeLa cells were probed, the cross reaction of anti-(Lp)-tektin B with HeLa keratins was eliminated by more than 98% within 2 min, suggesting that tektins have epitopes in common with the end domains of certain keratins.
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PMID:Relationship between tektins and intermediate filament proteins: an immunological study. 258 96

Solid and papillary epithelial neoplasms of the pancreas from six female patients were studied using immunohistochemistry and electron microscopy to define better their histogenesis. The tumors ranged in diameter from 5 to 15 cm (average: 9 cm), and, on cross section, most had areas of hemorrhage and necrosis, sometimes extensive. Microscopically, there was a solid and pseudopapillary pattern, with tumor cells typically having ovoid nuclei with delicate folding and indistinct nucleoli. Of note were the following: a relatively low mitotic rate (range: 0-6/20 hpf), the presence of hyaline globules (four of six cases), and collections of foam cells (three of six cases). Staining for cytoplasmic argyrophil granules was negative in each case. Ultrastructurally, the solid and papillary epithelial neoplasms of the pancreas showed evidence of acinar or ductular differentiation. Two contained zymogen granules, one had intermediate filaments (probably keratin), and three had abundant rough endoplasmic reticulum and mitochondria. Immunostaining was positive for chymotrypsin (six of six cases), trypsin (four of six), and amylase (three of six). None was positive for alpha-1-antitrypsin, neuron-specific enolase, pancreatic polypeptide, gastrin, glucagon, somatostatin, or insulin. The findings support an origin from exocrine pancreas, and follow-up indicates a low rate of malignancy, with local recurrence in two of the six patients.
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PMID:Solid and papillary epithelial neoplasm of the pancreas. An ultrastructural and immunocytochemical study of six cases. 381 76

Insoluble epidermal proteins (possibly keratin), previously considered inert to enzyme action, were solubilized by either trypsin or chymotrypsin. Cleavage of the disulfide bonds prior to enzymatic action is not necessary. In addition, the enzymatic action on intact epidermis is not influenced by the presence or absence of endogenous lipids, soluble proteins, peptides, or amino acids. Solubilization of epidermal protein by chymotrypsin is inhibited by the supernatant solution of the homogenized epidermis.
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PMID:Enzymatic solubilization of insoluble proteins at neutral pH. 602 48


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