Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The size of androgen receptors from rat ventral and dorsal prostate, dorsal prostate (Dunning) tumor, testis, epididymis, and seminal vesicle was determined using Sephadex G-200 chromatogrpahy and sucrose gradient centrifugation. The protease inhibitor diisopropyl fluorophosphate (DFP) was used to minimize receptor breakdown. An 8-9 S, 85 to 106 A receptor (Mr = 280,000 to 365,000; f/fo = 1.9 to 2.4) observed in unfractionated cytosol prepared in low ionic strength buffer with or without DFP is in equilibrium with a 4.5-5 S, 58 A form (Mr = 117,000; f/fo = 1.8) observed at salt concentrations greater than 0.1 M KCl. Receptor partially purified using (NH4)2SO4 or phosphocellulose chromatography in the absence of DFP was present as smaller fragments of 3.6 S, 37 A and 3.0 S, 23 A. Similar fragments could be generated from the 4.5 S or 8 S receptor by mild trypsin treatment. In addition, ventral prostate contains a DFP-insensitive enzyme which specifically converts the 4.5 S, 58 A receptor to the 3.6 S 37 A fragment. The DFP-insensitive enzyme is partially inhibited by rabbit bile and appears similar to the enzyme seminin, a secretory protein of human prostate. Androgen receptor isolated in the presence of DFP from nuclei labeled in vivo is predominantly 4.5 S, 58 A, with smaller forms (37 and 23 A) appearing in the absence of DFP. The 4.5 S, 58 A nuclear receptors were also in equilibrium with a large 8 S form. Receptor breakdown by DFP-insensitive and sensitive proteases appears to be an in vitro phenomenon. Furthermore, the size of the androgen receptor is not significantly changed during receptor migration from cytoplasm to nucleus.
 ...
PMID:Effects of proteases and protease inhibitors on the 4.5 S and 8 S androgen receptor. 44 15

PSA is a 34-kd 240-amino acid glycoprotein produced by the prostatic epithelial cells. It is a member of the glandular kallikrein gene family and has a high sequence homology with human glandular kallikrein (hGK-1). PSA is a serine protease and has chymotrypsin-, trypsin-, and esterase-like activities. It is secreted into the seminal fluid where it degrades two seminal vesicle proteins that are important components of the semen coagulum, thus playing an important role in semen liquefaction. The production of PSA protein appears to be under the control of circulating androgens acting through the androgen receptor. Therefore, the significance of a low serum PSA value in a patient who has undergone previous antiandrogen therapy may not be the same as that for a patient who has not received endocrine treatment.
 ...
PMID:Prostate-specific antigen and prostatic acid phosphatase: biomolecular and physiologic characteristics. 171 6

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.
 ...
PMID:Immunohistochemical study of lysozyme, alpha 1-anti-chymotrypsin, tissue polypeptide antigen, keratin and carcinoembryonic antigen in effusion sediments. 243 1

Immunoperoxidase stains were performed on normal and neoplastic tissue from prostate, colon, thyroid, lung, nerve, uterus, and placenta embedded in both plastic (glycolmethacrylate [GMA]) and paraffin. Positive results in plastic section were obtained for carcinoembryonic antigen (CEA), keratin, epithelial membrane antigen (EMA), thyroglobulins, S-100, prostate-specific antigen, human chorionic gonadotrophin (HCG), and beta-HCG. More delicate staining with more precise localization of antigens is noted. Superior (paraformaldehyde) fixation and cold processing followed by GMA polymerization (4 degrees C) allow for optimum antigen survival. After fixation, tissue processing involves a series of 0.1 mol/L phosphate buffer rinses with sucrose and ammonium chloride in a conventional dip-and-dunk processor placed in a 4 degrees C cold room. Acetone dehydrations are used before GMA infiltration, cold polymerization, and sectioning. Before immunoperoxidase staining, the plastic section is digested in .25% bovine trypsin for ten minutes. The immunoperoxidase methods described can be useful when small biopsies are routinely embedded in plastic to obtain improved histologic (hematoxylin-eosin) sections. There may also be research applications in quantifying antigen expression in benign, dysplastic, and neoplastic tissues by examining the stains under high power.
 ...
PMID:Antigen localization in immunoperoxidase-stained plastic-embedded soft tissues. 245 78

Based on recent studies indicating that human glandular kallikrein-1 (hGK-1) mRNA was present in the prostate, we have undertaken to determine whether the prostate contained trypsin-like proteases with properties compatible with those deduced from hGK-1 gene nucleotide sequence. The first series of experiments showed that only minimal levels of trypsin-like enzymatic activity, determined with synthetic substrates, were present in chromatographic fractions of prostatic glycoproteins having a molecular weight in the range expected for hGK-1, i.e., 25,000-35,000. Because of this, we used [3H]diisopropylfluorophosphate (DFP) labeling alone or in the presence of various serine-protease inhibitors to identify trypsin-like proteases in the prostate. Two-dimensional gel electrophoresis of prostatic glycoproteins showed the presence of minor spots of 18-32 kDa. These spots were slightly more acidic than were those of prostate specific antigen (PSA) and were completely inhibited by preincubation with tosyl lysine chloromethyl ketone and p-nitrophenyl-p-guanidobenzoate in contrast to PSA spots that were not affected by these treatments. When a similar procedure was applied to total cytosolic proteins instead of glycoproteins, an additional 30 kDa DFP binding protein was observed. This relatively abundant protein was much more acidic than was PSA and was not inhibited by any of the protease inhibitors tested. In conclusion, this study has permitted us to demonstrate the presence of two sets of proteins that have physicochemical properties compatible with those that can be deduced from the information contained in the hGK-1 gene.
 ...
PMID:Looking for human glandular kallikrein-1 in the prostate. 248 May 85

We have developed a sensitive and specific radioimmunoassay which allows the detection of human glandular kallikrein in biologic fluids at a level of 40 pg/ml. The antisera did not recognize human plasma kallikrein and glandular kallikrein from other species including marmoset. Furthermore the antibody did not bind pro-kallikrein but was specific for the trypsin activated kallikrein. The antibody inhibited the kininogenase activity of standard kallikrein incubated with human kininogen. However active kallikrein inhibited by inhibitors bound at the active site is still detectable, indicating that the antibody is specific for the structure of the active form but not for the active site. In normotensive subjects, daily urinary kallikrein excretion increased with age until 30, then a decrease was observed. In renal transplanted recipients a progressive increase of the active form was found. A low concentration of immunoreactive active kallikrein was detected in lymphatic fluids of patients suffering from acute pancreatitis treated by lymphatic drainage; although this kallikrein is the active immunoreactive form, a very weak kininogenase activity was measured, suggesting a partial inhibition by anti-proteases. These data provide complementary evidence for the physiological and pathological role of glandular kallikrein.
 ...
PMID:Direct radioimmunoassay of active and inactive human glandular kallikrein: some physiological and pathological variabilities. 266 24

A proteinase which can activate human, dog and rat plasminogen to plasmin has been isolated from the urine of female rats, using affinity chromatography on benzamidine-coupled Sepharose. Inhibition by diisopropylfluorophosphate, tosyl-L-lysine chloromethylketone and benzamidine classified the enzyme as trypsin-like. The proteinase has weak activity on alpha-casein and hemoglobin, but will not lyse fibrin clots. It readily cleaves arginyl amides, including synthetic substrates specific for human glandular kallikrein and other serine proteinases. A chromogenic substrate for human urokinase (pyro Glu-Gly-Arg-pNA) is a poor substrate for the rat proteinase. Characteristics of the enzyme, such as its molecular weight (25 900), kinetic parameters and inhibition by aprotinin, indicate that this proteinase is esterase A, described by several investigators. Esterase A is shown not to be a true urinary plasminogen activator but rather is a unique arginine-specific proteinase. Urokinase-like and kallikrein-like activity are part of a broader proteolytic activity displayed by this enzyme.
 ...
PMID:Esterase A is a proteinase from rat urine that can activate plasminogen. 623 43

PSA is a 34-kDa 240-amino-acid glycoprotein produced exclusively by prostatic epithelial cells. PSA is a serine protease, is a member of the kallikrein gene family, and has a high sequence homology with human glandular kallikrein. It has chymotrypsin-, trypsin-, and esterase-like activities. In the serum it is present mainly in a complex form with alpha 1-antichymotrypsin. It is secreted in the seminal plasma and is responsible for liquefaction of the seminal coagulum. The production of PSA proteins appears to be under the control of circulating androgens acting through the androgen receptors. The PSA gene is up-regulated predominantly by androgens at both the protein and mRNA levels. DRE causes minimal changes in the PSA level, while prostate massage, ultrasonography, systoscopic examination, and prostate biopsy can all cause clinically significant elevations. Other conditions, such as prostatitis, prostate intraepithelial neoplasia, acute urinary retention, and renal failure can also elevate the PSA level. The value of PSA as a screening tool is questionable because of the great deal of overlap in PSA levels between BPH and prostate cancer. However, if used in men over 50, in conjunction with DRE and/or ultrasonography, it may become a vital part of the early detection program. PSA's role in determining the clinical and pathological stage is also limited, in spite of the direct correlation between the pathological stage and the PSA level, because of great overlap in the PSA levels in various stages. The most important clinical utility of PSA is in monitoring patients after definitive therapy. PSA is most sensitive and reliable in the detection of a residual tumor, possibly recurrence, or disease progression following treatment, irrespective of the treatment modality. PSA can accurately predict the tumor status and can detect recurrence several months before its detection by any other method. PSA is also a very sensitive and specific immunohistochemical marker for tumors of prostatic origin. Compared to PAP, PSA is a more precise and meaningful marker in all clinical situations. With the development of ultrasensitive assays and the adoption of an international standard PSA calibrator, so that results from multicenter studies can be compared, PSA could become one of the most useful tumor marker in cancer biology.
 ...
PMID:Prostatic specific antigen. 753 74

We attempted to identify the presence of kallikrein in human vascular tissue obtained from patients undergoing surgery. Sections of thoracic (n = 9) and abdominal aorta (n = 6), renal artery (n = 6), and saphenous vein (n = 17) were rinsed with 0.01 mol/L Tris-HCl buffer, cleaned, minced, and homogenized at 4 degrees C. The homogenates were centrifuged and supernatants were assayed for protein content and for active and total (trypsin activation) enzymatic activity on the peptide H-D-Val-Leu-Arg-paranitroanilide (S2266), a synthetic substrate for glandular kallikrein. Enzymatic activity was inhibited by aprotinin and polyclonal antibodies against human glandular kallikrein. Kallikrein was resistant to soybean trypsin inhibitor and had an optimum pH of 8.2. A significant correlation was found between the amidolytic and kininogenase activities measured on S2266 and dog kininogen, respectively (r = 0.83, P < .01). The kallikrein-like enzyme was present mainly in the inactive form. Higher levels were found in the homogenates of renal artery (active: 190 +/- 36, total: 5036 +/- 908 pkat/g protein) than in those of thoracic (active: 38 +/- 9, total: 973 +/- 350 pkat/g protein) and abdominal aorta (active: 44 +/- 10, total: 3031 +/- 709 pkat/g protein). In the homogenates of saphenous vein, active and total enzymatic activities averaged 188 +/- 90 and 2003 +/- 450 pkat/g protein, respectively. A significant inverse correlation was found between the levels of total enzymatic activity in saphenous vein homogenates and mean blood pressure values (r = 0.78, P < .005). These results suggest that a kallikrein-like enzyme is present in human vasculature.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:A kallikrein-like enzyme in human vascular tissue. 851 58

In an effort to isolate genes with down-regulated expression at the mRNA level during oncogenic transformation of human mammary epithelial cells (MECs), we performed subtractive hybridization between normal MEC strain 76N and its radiation-transformed tumorigenic derivative 76R-30. Here, we report the isolation of cDNA clones corresponding to a 1.4-kb mRNA species that is abundantly expressed in 76N cells but is drastically reduced in 76R-30 cells. Based on its selective expression in MECs compared with fibroblasts, the corresponding gene is designated NES1 (normal epithelial cell-specific 1). Sequence analysis of the full-length NES1 cDNA clones revealed it to be a novel gene with a predicted polypeptide of 30.14 kilodaltons; in vitro transcription and translation confirmed this prediction. Database searches revealed a 50-63% similarity and 34-42% identity with several families of serine proteases, in particular the trypsin-like proteases, members of the glandular kallikrein family (including prostate-specific antigen, nerve growth factor gamma, and epidermal growth factor-binding protein) and the activators for the kringle family proteins (including the human tissue plasminogen activator and human hepatocyte growth factor activator). Importantly, all of the residues known to be crucial for substrate binding, specificity, and catalysis by the serine proteases are conserved in the predicted NES1 protein, suggesting that it may be a protease. An antipeptide antibody directed against a unique region of the NES1 protein (amino acids 120-137) detected a specific 30-kilodalton polypeptide almost exclusively in the supernatant of the mRNA-positive MECs, suggesting that NES1 is a secreted protein. The 1.4-kb NES1 mRNA was expressed in several organs (thymus, prostate, testis, ovary, small intestine, colon, heart, lung, and pancreas) with highest levels in the ovary; a 1.1-kb transcript was found in the pancreas. Although expression of the NES1 mRNA was observed in all normal and immortalized nontumorigenic MECs, the majority of human breast cancer cell lines showed a drastic reduction or a complete lack of its expression. The structural similarity of NES1 to polypeptides known to regulate growth factor activity and a negative correlation of NES1 expression with breast oncogenesis suggest a direct or indirect role for this novel protease-like gene product in the suppression of tumorigenesis.
 ...
PMID:Identification of a novel serine protease-like gene, the expression of which is down-regulated during breast cancer progression. 876 36


1 2 3 4 5 Next >>