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

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urogastrone is a potent inhibitor of gastric acid secretion which is present in human urine. Its existence has been known for over 30 years but it has only recently been isolated in a sufficiently pure form for detailed structural studies to be undertaken. Two separate polypeptides beta- and gamma-urogastrone were isolated. The structures were established by carrying out enzymic degradations of S-carboxymethyl and S-carboxamidomethyl derivatives with trypsin, chymotrypsin, thermolysin and a protease derived from the fungus Armillaria mellea. Sequences of the smaller peptides thus obtained were determined by the dansyl Edman method. Partial acid hydrolysis of urogastrone itself gave fragments containing single intact disulphide bonds, and oxidation then allowed the direction of individual bonds to be established. Beta-Urogastrone was shown to be a 53-amino acid residue polypeptide containing three disulphide bonds, and gamma-urogastrone had an identical sequence but lacked the C-terminal arginine residue. Urogastrone was subsequently found to be structurally related to mouse epidermal growth factor in that 37 of the 53 residues were commonly located in each polypeptide. Furthermore, as both peptides has similar effects upon gastric acid secretion and upon epidermal growth, urogastrone was also a human epidermal growth factor. The 16 variable residues were spread across the molecule, all apart from two were compatible with single base changes in the triplet condons, and the overall effect was to make uorgastrone more acidic than EGF. The smallest biologically active unit has not been defined but at least six residues can be removed from the C-terminus without causing a reduction in potency.
...
PMID:The primary structure of human urogastrone. 30 79

Human epidermal growth factor (hEGF) has previously been isolated from urine and appears to be identical to beta-urogastrone (UG), an inhibitor of stimulated gastric acid secretion. A high molecular weight (HMW) form of hEGF/UG has recently been found in human urine which is fully immunoreactive but is less bioactive as measured by receptor binding activity. A specific arginine esterase, the EGF-binding protein from mouse submandibular glands, was capable of cleaving HMW-hEGF to yield a small molecular weight (SMW)-hEGF with full immunoreactivity and bioactivity, whereas trypsin produced a SMW-hEGF with much less bioactivity. SMW-hEGF produced by the arginine esterase appeared to be immunologically, biologically (both by receptor binding and mitogenic activity) and chromatographically similar to highly purified hEGF. These data suggest that HMW-hEGF may play a precursor role in the biosynthesis of hEGF/UG in man.
...
PMID:Conversion of high molecular weight human epidermal growth factor (hEGF)/urogastrone (UG) to small molecular weight hEGF/UG by mouse EGF-associated arginine esterase. 31 37

Human hair follicles were isolated from the scalp by dispase and collagenase treatment and dispersed into a cell suspension by trypsin. These cells proliferated well and could be subcultured 7 to 8 times. The medium used was MCDB 153 HAA medium further supplemented with some amino acids, hydrocortisone, insulin, EGF, and bovine brain extract. The concentration of Ca++ was adjusted to 0.1 mM. Immunohistochemically, these cells were proved to possess keratins specific to hair forming cells.
...
PMID:In vitro keratin expression of hair cells. 128 73

The autocrine growth factor(s) was isolated from serumfree conditioned medium of rat sarcoma (XC) cells. Autocrine activity was enriched by ultrafiltration using Amicon YM 10 membrane, extraction with 1 M acetic acid and partially purified (650-fold) by chromatography on Bio-Gel P-100 and P-60. The final recovery of the autocrine factor(s) was 4 micrograms from 1800 ml of the conditioned medium (a yield of 6%). The factor(s) with molecular weight 6-10 kDa was heat and acid stable but inactivated by trypsin and dithiothreitol. It stimulated anchorage-dependent (but not anchorage-independent) growth of XC cells as well as untransformed, established lines of rat (NRK) and mouse (3T3) cells. The results obtained may suggest that autocrine factor(s) produced by XC cells can be one of EGF-like or/and insulin-like growth factors.
...
PMID:Anchorage-dependent growth factor(s) produced by rat sarcoma (XC) cells. 128 29

A human prostate cancer model was established by inoculating a prostate specific antigen (PSA)-producing LNCaP cell line with either prostate or bone fibroblasts. Alternatively, this human prostate cancer model can also be established by inoculating LNCaP cells with growth factor(s) (GFs) and extracellular matrix (ECM) immobilized on Gelfoam. The resulting LNCaP tumors were used to evaluate PSA production and excretion in athymic hosts. This model was also employed to examine the biochemical nature of mesenchymal cell-derived growth-promoting protein(s) and to assess the efficacy of potential chemotherapeutic agents. Because of the propensity of human prostate cancer to metastasize to the bone, this study defined a 1.0 M NaCl-eluted fraction, MS1, from the conditioned medium of a bone stromal cell line (MS) by heparin-affinity column chromatography. The growth-promoting activity was assayed both in vivo (e.g., tumor formation) and in vitro (e.g., soft agar colony formation). We found that the growth-promoting activity was trypsin- and heat-sensitive, and partially degraded by acid and dithiothreitol. Immunochemical studies indicated that the polyclonal antibody raised against MS1 blocked the growth-promoting effect elicited by the bone-conditioned media. This growth-promoting factor was found to be immunochemically dissimilar to KGF, HGF, and bFGF. However, addition of bFGF, HGF and NGF, but not aFGF, TGF beta, IGF1, IGF2, PDGF, EGF, TGF alpha and KGF, stimulated anchorage-independent growth of prostate cells, a condition closely parallel to tumor formation in vivo. We found that the MS1 fraction also contained fibronectin and tenascin but not laminin or collagen IV.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Human prostate cancer model: roles of growth factors and extracellular matrices. 128 80

The laminin-nidogen complex, the most abundant noncollagenous component of basement membranes, was recently shown to be a specific substrate for tissue transglutaminase (Aeschlimann, D., and Paulsson, M. (1991) J. Biol. Chem. 266, 15308-15317). Saturation experiments to determine the number of amine acceptor site(s) indicated a single reactive Gln residue in nidogen and none in laminin. Murine nidogen was labeled with [3H]putrescine in the tissue transglutaminase-catalyzed reaction, and two major radioactively labeled fragments, T70 and T40, were isolated after limited trypsin digestion. NH2-terminal sequencing showed that T40 is contained in T70 and corresponds to the rodlike structure of nidogen, made up of epidermal growth factor-like repeats. Three radioactively labeled peptides, obtained by extensive trypsin digestion of reduced and alkylated T40, were sequenced. In all a single residue, Gln726, was found to contain label. Sequencing of additional peptides, obtained after further treatment of the largest radioactively labeled peptide with endoproteinase Asp-N, gave the same result. Gln726 is located in an exposed loop between the second and the third EGF-like repeat in nidogen. This site is also conserved in the human sequence.
...
PMID:Identification of Gln726 in nidogen as the amine acceptor in transglutaminase-catalyzed cross-linking of laminin-nidogen complexes. 135 Jul 83

We have recently developed a kinetically controlled, step-wise affinity cross-linking technique for specific, high-yield, covalent linkage of murine epidermal growth factor (mEGF) via its N terminus to the EGF receptor. EGF receptor from A431 cells was cross-linked to radiolabeled mEGF (125I-mEGF) by this technique and the 125I-mEGF-receptor complex was purified and denatured. Tryptic digestion of this preparation gave rise to a unique radiolabeled peptide that did not comigrate with trypsin-treated 125I-mEGF in SDS/Tricine gels but that could be immunoprecipitated with antibodies to mEGF. The immunoprecipitated peptide was isolated by electrophoresis in SDS/Tricine gels, eluted, and sequenced. The sequence was found to correspond to that of a tryptic peptide of the EGF receptor beginning with Gly-85, which is in domain I, a region N terminal to the first cysteine-rich region of the receptor. Selective loss of signal in the 17th sequencing cycle suggests that the point of attachment of N-terminally modified 125I-mEGF to the receptor is Tyr-101. The data presented here provide identification by direct protein microsequencing of a site of interaction of EGF and the EGF receptor.
...
PMID:Direct identification of residues of the epidermal growth factor receptor in close proximity to the amino terminus of bound epidermal growth factor. 138 Jan 67

We have previously reported that human placental cytotrophoblasts (C-cells) contain nuclear 3,5,3'-triiodo-L-thyronine (T3) receptors. Using a C-cell culture system, the present study was undertaken to clarify some of the effects of T3 and EGF on trophoblastic cells. C-cells were purified from human term placenta by treatment with trypsin-DNAse and percoll gradient centrifugation aggregated, then fused, differentiating into multinuclear syncytiotrophoblasts (S-cells) with incubation times up to 96 h in vitro. As the incubation time increased, the number of immunocytochemically reactive cells with antibodies to hCG-alpha, hCG-beta and hPL increased. Anti-EGF antibody reacted only with the initial C-cells, while anti-EGF receptor antibody reacted only with fused S-cells. Maximum secretion of hCG and hCG-alpha by the cultured cells was evident only when the cells were cultured in T3 (10(-8)M) or EGF (10 ng/ml) containing medium. When the initial cells were exposed to 10(-8) M T3 from 0 to 48 h of incubation, the secretion in 48-96 h was significantly accelerated. However, exposure from 48 to 96 h had no effect on peptide excretion. Although an exposure of these cells to 10 ng/ml EGF during 48-96 h of incubation stimulated the secretion of hCG and hCG-alpha, 0-48 h exposure did not produce any positive effect regardless of incubation time. These results indicated that the main target cell of T3 is the C-cell, while that of EGF is the S-cell. Furthermore, it is suggested that the interaction between T3 and its receptor facilitated functional cell differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Studies on the effect of thyroid hormone and epidermal growth factor on the cultured human cytotrophoblast. 179 34

A new method of long-term culture of cytotrophoblast cells in serum-free medium has been developed. Cytotrophoblast cells were isolated with cold trypsin and purified by unit gravity sedimentation through BSA density gradients. The cells were cultured in the FD medium with supplement of EGF, insulin, transferrin and sodium selenite. They could survive over three weeks. The results showed that both EGF and insulin stimulated hCG and progesterone secretion and that sodium selenite elevated hCG output but not progesterone secretion. Transferrin produced synergistic effect with EGF and insulin on hCG and progesterone secretion but it was ineffective when used alone. This study demonstrates that the four growth factors mentioned above are essential for the survival of cytotrophoblast cells in vitro. It is therefore suggested that EGF, insulin and selenium may possibly be involved in the regulation of hCG and progesterone secretion in the human placenta.
...
PMID:Study on reproductive endocrinology of human placenta--culture of highly purified cytotrophoblast cell in serum-free hormone supplemented medium. 180 45

P3 cell lines can be grown in protein- and lipid-free synthetic medium. Using the P3 cell culture, we have shown that these cells produce autocrine growth factors and cell-substrate attachment factors. Because the cultured cells produce proteinase-inhibitor, spent medium is applicable for inactivating the action of trypsin at the time of cell passage. In addition, we have tried to cultivate various types of cells in serum-free media on the market (ASF103, ASF104 and GIT). Many cell lines can grow in these media, but inoculum dependency is observed in some cell lines. Production of monoclonal antibody by a hybridoma cell line is rather enhanced in these media. These media can be preserved at 4 degrees C or -20 degrees C for a relatively long period. These media added with EGF support the growth of Syrian hamster embryo cells at an early passage. The growth of human diploid fibroblasts in GIT medium added with EGF is a little less compared in a serum-containing medium.
...
PMID:[Cultivation of mammalian cells in serum-free media]. 181 43


1 2 3 4 5 6 7 Next >>

---