Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.27 (thermolysin)
 1,894 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A novel form of free human chorionic gonadotrophin beta-subunit (hCG beta) was found in serum from ElBre, a woman with epidermoid carcinoma of unknown origin. ElBre hCG beta was larger than standard (pregnancy urine) hCG beta when analysed by gel chromatography (apparent molecular weight 54 000 vs 44 000). This size difference appeared to be due to a larger carboxyterminal extension (CTE) of ElBre hCG beta since thermolysin cleavage of the CTE from standard hCG beta and Elbre hCG beta yielded core products of the same size. Oligosaccharides, O-linked to serine or threonine, were present in ElBre hCG beta, presumably on its CTE as judged by the complete binding of desialylated ElBre hCG beta to immobilized peanut agglutinin (this lectin is specific for terminal galactose linked beta 1----3 to N-acetylgalactosamine, a disaccharide exposed after desialylation of the O-linked oligosaccharides of standard hCG beta). ElBre hCG beta, however, was incompletely recognized by antisera specific for the CTE of standard hCG beta, especially the carbohydrate-sensitive antiserum R141. The O-linked oligosaccharides of standard hCG beta are heterogeneous in size; 13% are of the largest (hexasaccharide) form. In contrast, over 50% of the O-linked oligosaccharides in hCG beta from the JAr choriocarcinoma cell line are hexasaccharides. Like desialylated ElBre hCG beta, desialylated JAr hCG beta bound completely to peanut agglutinin, but was incompletely recognized by antisera to the hCG beta-CTE. Furthermore, JAr hCG beta was intermediate in size between standard hCG beta and ElBre hCG beta when analysed by gel chromatography (apparent molecular weight 49 000).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A novel form of ectopic human chorionic gonadotrophin beta-subunit in the serum of a woman with epidermoid cancer. 241 52

The photochemical reaction of MgADP-vanadate with the active site of myosin has been used to place a serine at the binding site for the gamma-phosphate of ATP. Irradiation of the MgADP-vanadate myosin subfragment 1 transition state-like complex with UV light specifically photooxidizes the hydroxyl group of a serine residue to an aldehyde (Cremo, C. R., Grammer, J. C., and Yount, R. G. (1988) Biochemistry 27, 8415-8420). Reduction of photooxidized myosin with Na-B3H4 gave only 3H-labeled serine. Here, subsequent extensive proteolytic digestion of 3H-labeled myosin subfragment 1 with trypsin and thermolysin yielded two 3H-labeled peptides, both of which contained the sequence Gly-Glu-Ser-Gly-Ala-Gly-Lys-Thr, in which all the 3H was associated with the serine. This sequence is conserved in all myosin heavy chains sequenced to date and corresponds to residues 178-185 in the rabbit myosin heavy chain (Tong, S. W., and Elzinga, M. (1983) J. Biol. Chem. 21, 13100-13110). These results place Ser-180 at the gamma-phosphate-binding site for ATP and indicate that the glycine-rich loop around the serine provides essential elements of the phosphate-binding site for ATP in all myosin molecules. Such a role was previously suggested based on the common sequence Gly-X-X-X-X-Gly-Lys-Thr/Ser, found in myosin and many other nucleotide-binding enzymes (Walker, J. E., Saraste, M., Runswick, M. H., and Gay, N. J. (1982) EMBO J. 1, 945-951).
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PMID:Direct chemical evidence that serine 180 in the glycine-rich loop of myosin binds to ATP. 252 83

The E7 protein of human papillomavirus type 16 (HPV16) transforms cultured cells and cooperates with the ras or fos oncogenes in the transformation of primary cells. In this study we have investigated the phosphorylation of E7. When we immunoprecipitated E7 from CaSki cells with a rabbit polyclonal antiserum to a bacterial fusion protein (trpE-E7), we found that E7 was phosphorylated at serine residues contained in five characteristic thermolysin peptides. Immunoprecipitated E7, and fusion proteins harboring the E7 protein from various HPV types, could all be specifically phosphorylated in vitro by the ubiquitous, growth factor-activated casein kinase II (CKII). Comparative peptide mapping showed that the sites of in vivo and in vitro phosphorylation are the same. CKII was shown previously to specifically phosphorylate serine or threonine residues within a cluster of acidic amino acids. The E7 protein contains such a sequence between amino acids 30 and 37. When a synthetic peptide corresponding to this region of E7 was phosphorylated by CKII in vitro, its thermolysin digestion products were the same as those in the phosphorylated E7 protein. We conclude that E7 is phosphorylated in vivo only at serines within the predicted CKII site and that CKII, or a CKII-like enzyme, participates in the reaction. Both the E1A and SV40 large T proteins contain similar CKII consensus sites proximal to the regions required for their associations with the retinoblastoma gene product (p105Rb). Thus it is conceivable that CKII phosphorylation can modulate the interaction between the transforming proteins and the retinoblastoma gene product.
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PMID:The E7 protein of human papillomavirus type 16 is phosphorylated by casein kinase II. 256 89

The number of free cysteines in each polypeptide of acetylcholine receptor from the electric organ of Torpedo californica has been assessed by alkylating the native protein with N-ethylmaleimide and iodoacetamide during homogenization of the tissue and alkylating the polypeptides with N-ethylmaleimide as they were unfolded in solutions of dodecyl sulfate. The cysteines unavailable for alkylation could be accounted for as specific cystines, connecting positions in the amino acid sequences of the individual polypeptides. Unreduced, alkylated polypeptides of acetylcholine receptor were digested with thermolysin or trypsin. Cystine-containing peptides in the chromatograms of the digests were identified electrochemically by the use of a dual gold/mercury electrode. Three thermolytic peptides and three tryptic peptides have been isolated from these digests and shown to contain intact cystines that were originally present in the native protein. The majority of these peptides contained an intact, intramolecular cystine connecting two cysteines in locations homologous to cysteines 128 and 142 from the alpha polypeptide. Each of these cystines from each of the polypeptides of acetylcholine receptor was isolated in at least one peptide, respectively. Each of these cystine-containing peptides also contained glucosamine. It can be concluded that each asparagine in the sequence Asn-Cys-Thr/Ser, which occurs in the respective, homologous location in every polypeptide, is glycosylated even though a cystine sits between the asparagine and the threonine or serine. In addition, the existence of the cystine connecting the adjacent cysteines, alpha 192 and alpha 193, in the alpha subunit of acetylcholine receptor [Kao, P. N., & Karlin, A. (1986) J. Biol. Chem. 261, 8085-8088] has been confirmed.
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PMID:Assessment of the number of free cysteines and isolation and identification of cystine-containing peptides from acetylcholine receptor. 274 50

A rapid phosphorylation of tyrosine hydroxylase occurs in the PC12 nerve-like clonal cell line in response to nerve growth factor (NGF), epidermal growth factor (EGF), dibutyryl-cAMP, cholera toxin, phorbol- 12-myristate-13-acetate (PMA), or potassium depolarization in the presence of calcium ions. Complete tryptic digestion and two-dimensional peptide mapping reveals four available sites of phosphorylation in the enzyme. Phosphoamino acid analysis demonstrates that serine is the amino acid residue phosphorylated in each peptide. Specific phosphorylation of each of the four sites is achieved by different subsets of the above agents. One peptide site is phosphorylated in response to EGF alone. A second site is phosphorylated only in response to NGF, cholera toxin or dibutyryl-cAMP. A third site is phosphorylated only in response to potassium depolarization and requires the presence of extracellular Ca2+. The fourth site is the only site phosphorylated in response to PMA. These data indicate that at least 4 distinct kinase systems can act to phosphorylate tyrosine hydroxylase in PC12 cells. The PMA-stimulated peptide site is also phosphorylated in response to every one of the other agents. Further proteolytic digestions and phosphopeptide mapping of this common peptide, using Staphylococcus V8 protease and thermolysin, did not generate different phosphopeptides resulting from the different agents. These data suggest that the phosphorylation of this common peptide in response to all of the agents may be mediated by a common kinase, and, hence, that tyrosine hydroxylase phosphorylation by some agents may be mediated by two kinases. Although phosphopeptide maps of tyrosine hydroxylase resulting from cAMP elevation or NGF are qualitatively similar, quantitative differences exist, suggesting differential regulation of the same kinases by these agents. Tyrosine hydroxylase was found to be activated 2--4-fold in response to each phosphorylating agent. Thus, NGF and EGF present novel, natural means of regulating the activation state of tyrosine hydroxylase in responsive neurons.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Nerve growth factor and other agents mediate phosphorylation and activation of tyrosine hydroxylase. A convergence of multiple kinase activities. 286 43

The blood cell of the horseshoe crab, Limulus, is packed with granules that can be stimulated to release their contents by exocytosis. We have identified a family of proteinase inhibitors in the released materials. Included is a factor similar to the alpha 2-macroglobulin homologue present in the plasma and acid-stable and acid-instable active-site inhibitors. The acid-stable factor is active against both serine (trypsin, chymotrypsin) and metal (thermolysin) proteinases. The trypsin- and chymotrypsin-inhibitory activity has a molecular weight of 6100, as determined by gel-filtration chromatography.
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PMID:Proteinase inhibitory activity released from the horseshoe crab blood cell during exocytosis. 298 12

A metalloproteinase inhibitor present in human rheumatoid synovial fluid was purified by a combination of heparin-Sepharose chromatography, concanavalin A-Sepharose chromatography, ion-exchange chromatography and gel filtration. The Mr of the purified inhibitor was 28000 by SDS/polyacrylamide-gel electrophoresis and 30000 by gel filtration. The inhibitor blocked the activity of the metalloproteinases collagenase, gelatinase and proteoglycanase, but not thermolysin or bacterial collagenase. The serine proteinase trypsin was not inhibited. The inhibitory activity was lost after treatment with trypsin (0.5 micrograms/ml) at 37 degrees C for 30 min, 4-aminophenylmercuric acetate (1 mM) at 37 degrees C for 3 h, after incubation for 30 min at 90 degrees C and by reduction and alkylation. These properties suggest that the inhibitor closely resembles the tissue inhibitor of metalloproteinases ('TIMP') recently purified from connective-tissue culture medium.
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PMID:Purification of a metalloproteinase inhibitor from human rheumatoid synovial fluid. 300 Mar 52

Limited cleavages of human C1r by extrinsic proteases of various specificity (plasmin, elastase, chymotrypsin, thermolysin) yield dimeric associations of two globular domains, each comprised of the intact B chain disulfide linked to gamma, the C-terminal fragment of the A chain. These (gamma-B)2 domains, which are homologous to those obtained from C1r by autolytic cleavage [Villiers, C. L., Arlaud, G. J., & Colomb, M. G. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 4477-4481], represent the core of the C1r molecule and are associated with the catalytic properties of the serine active site. V8 protease also yields (gamma-B)2 associations, although additional cleavages occur in the B chain. Sequence analysis shows that all cleavages generating the gamma fragments occur within a 13-residue sequence extending from positions 274 to 286 of the C1r A chain. Chemical cross-linking with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide of the (gamma-B)2 catalytic domains obtained from C1r autolytic cleavage indicates that each gamma-B domain interacts with its neighbor in a "head to tail" configuration, the gamma region of one domain interacting with the B chain of the other domain, and conversely. No evidence is found of gamma-gamma or B-B interactions. Such a head to tail configuration, placed in the context of the model proposed for the C1s-C1r-C1r-C1s catalytic subunit of C1 [Colomb, M. G., Arlaud, G. J., & Villiers, C. L. (1984) Philos. Trans. R. Soc. London, B 306, 283-292], is compatible with autolytic activation of C1r through an intramolecular cross-mechanism and with subsequent activation of C1s by activated C1r.
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PMID:Molecular characterization of the catalytic domains of human complement serine protease C1r. 302 Dec 10

The primary structure of the Hypoderma lineatum collagenase was determined. Chymotrypsin digestion and thermolysin fragmentation of the chymotryptic core gave 30 and 5 peptides, respectively, accounting for all the residues of the protein. These peptides were aligned with overlapping peptides derived from tryptic and Staphylococcus aureus V8 proteinase digests. Hypoderma collagenase is a serine proteinase composed of 230 amino acids (Mr 25,223). It displays a high degree of sequential homology with the serine proteinases of the trypsin family, especially with another collagenolytic enzyme, the proteinase I of the crab Uca pugilator. The six half-cystinyl residues of Hypoderma collagenase correspond to 6 of the 10 half-cystinyl residues of chymotrypsin, and the residues forming the charge-relay system of the active site of chymotrypsin (His-57, Asp-102, and Ser-195) are found in corresponding regions. The prediction of the secondary structure of the collagenase is given.
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PMID:Complete amino acid sequence of the collagenase from the insect Hypoderma lineatum. 303 99

Thymus myosin, light chains and a synthetic peptide (S-S-K-R-A-K-A-K-T-T-K-K-R-P-Q-R-A-T-S-N-V-F-S) corresponding to the N-terminal sequence of smooth muscle myosin light chains were compared as substrates for calcium/calmodulin-dependent protein kinase (MLCK), calcium/phospholipid-dependent protein kinase (PKC), and a MgATP-activated protein kinase (H4PK) from lymphoid cells. All protein kinases catalyzed phosphorylation of the substrates although H4PK showed higher affinity for isolated light chains and the peptide. Phosphoamino acid analysis and analysis of thermolysin peptides established that PKC catalyzed phosphorylation of threonine-9 or 10. In addition, PKC and H4PK catalyzed phosphorylation at serine-19, the MLCK site. Collectively the data support the hypothesis that myosin filament assembly in nonmuscle cells may be regulated by a variety of calcium-dependent and calcium-independent protein kinases.
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PMID:Nonmuscle myosin phosphorylation sites for calcium-dependent and calcium-independent protein kinases. 308 Sep 87


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