Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat pulmonary surfactant contains apoproteins of molecular weights 38,000, 32,000, 26,000 and 10,000-12,000. The structural and metabolic interrelationships of these proteins are not clear as yet. In order to investigate if they arise from a single or multiple precursor protein (s), we isolated total poly(A)RNA from rat lungs, performed its translation in vitro in the presence of [35s]-methionine and reticulocyte lysate, immunoprecipitated the translation products with anti-rat surfactant antibody, and analyzed them by SDS-polyacrylamide gel electrophoresis and autoradiography. A single translation product of molecular weight 35,000 was detected. Since the antibody used in the immunoprecipitation recognizes the 38,000, 32,000 and 26,000 dalton proteins, it is concluded that at least these three proteins arise from the 35,000 dalton precursor by post-translational modifications.
 ...
PMID:In vitro translation of rat lung surfactant apoprotein mRNA. 388 5

A precursor protein associated with the formation of the citrulline-containing intermediate filaments of the hair follicle has been isolated and characterized. The protein, with a molecular weight of 190,000, was isolated from sheep wool follicles and purified until it yielded a single band on a SDS polyacrylamide gel. The Mr 190,000 protein has a high content of lysine and glutamic acid/glutamine residues and is rich in arginine residues, some of which, it is postulated, undergo a side chain conversion in situ into citrulline residues. Polyclonal antibodies were raised to the purified protein, and these cross-react with similar proteins from extracts of guinea pig and human follicles and rat vibrissae inner root sheaths. Tissue immunochemical methods have localized the Mr 190,000 protein to the trichohyalin granules of the developing inner root sheath of the wool follicle. We propose that the old term trichohyalin be retained to describe this Mr 190,000 protein. Immunoelectron microscopy has located the Mr 190,000 protein to the trichohyalin granules but not to the newly synthesized filaments. This technique has revealed that trichohyalin becomes associated with the filaments at later stages of development. These results indicate a possible matrix role for trichohyalin.
 ...
PMID:Trichohyalin, an intermediate filament-associated protein of the hair follicle. 395 55

It has been demonstrated previously that the acute phase reactant, serum amyloid A (SAA), is subject to degradation by surface membrane-associated proteinases of peripheral blood monocytes. However, monocytes obtained from the blood of patients with amyloidosis degraded SAA incompletely, leaving a cleavage product that, biochemically and immunologically, resembled the amyloid protein A (AA) deposited in their tissues. To investigate the role of fixed macrophages in amyloidogenesis and to establish more definitively that amyloid deposition is attributable to faulty processing of the precursor protein rather than aberrant synthesis, secondary amyloidosis was induced in C57BL/6J mice by serial injections of casein. Kupffer cells (KC) were isolated from livers of mice that had received 0, 8, 13, 18, and greater than 30 injections of the stimulant. The cells were cultured with SAA for 4, 8, and 18 h and then subjected to electron microscopy and enzyme analyses. The medium was analyzed by SDS-PAGE to determine the amount of residual SAA and/or the appearance of AA. KC of healthy animals degraded SAA completely whereas KC of stimulated mice showed increasing amounts of residual SAA and the appearance of the AA cleavage product. The AA peptide appeared in KC cultures early during the course of casein injections and before any amyloid could be demonstrated in the organs of the stimulated mice. The addition of KC isolated from healthy mice to cultures that had produced AA eliminated the abnormal peptide. The results, indicate that defective KC function precedes amyloidosis. The abnormal AA cleavage product formed by such cells is still susceptible to hydrolysis by normal cells. In addition, ultrastructural evidence is presented that suggests that KC may also play a role in fibrillogenesis of the AA protein.
 ...
PMID:Impaired Kupffer cell function precedes development of secondary amyloidosis. 398 70

gamma MSH, a putative hormone in the N-terminal region of the ACTH/beta-endorphin (beta-EP) precursor protein, was studied by RIA with an antiserum against gamma 3MSH in ACTH-producing mouse pituitary tumor cells, AtT-20/D16v. Serial dilution of the culture medium or the cell extract gave parallel lines to the standard curve in the RIA for gamma MSH. Rat median eminence extracts enhanced the release of gamma MSH-like immunoreactivity (gamma MSH-LI) concomitant with ACTH-like immunoreactivity (ACTH-LI) and beta-EP-like immunoreactivity (beta-EP-LI). Dexamethasone suppressed the release of gamma MSH-LI as well as ACTH-LI and beta-EP-LI. Gel exclusion chromatography of the culture medium and the cell extract has revealed that gamma MSH-LI consists of two peaks; one eluted near the elution position of beta-lipotropin and the other near the elution position of beta-EP. There was no peak corresponding to the elution position of synthetic gamma 3MSH. However, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) has demonstrated that gamma MSH-LI migrated at five positions with molecular weights of 31K, 21-23K, 16-17K, 13-14K, and 3.8K, respectively. The 31K gamma MSH coincided with the migration position of 31K ACTH of 31K beta-EP, and 21-23K gamma MSH coincided with the position of 21-23K ACTH on SDS-PAGE. The 16-17K gamma MSH coincided with the mouse 16K fragment (reported by Eipper and Mains) of ACTH-beta-lipotropin precursor protein in the migration in SDS-PAGE and in immunoreactivity to anti-gamma MSH antiserum. [3H]Glucosamine was incorporated into 16K, 13K, and 3.8K gamma MSH. These results suggest that AtT-20/D16v cells produce gamma MSH-LIs with molecular weights of 31K, 21-23K, 16-17K, 13-14K, and 3.8K, and they are secreted concomitantly with ACTH-LI and beta-EP-LI.
 ...
PMID:Characterization of gamma-melanotropin-like immunoreactivity and its secretion in an adrenocorticotropin-producing mouse pituitary tumor cell line. 628 79

Three murine mammary tumor virus (MuMTV)-producing epithelial cell lines derived from murine mammary tumors were examined in order to identify the MuMTV-specific cell surface antigens and their distribution on the cell surface, to study the kinetics of the MuMTV envelope precursor processing, virus assembly, and release, and to characterize the soluble MuMTV antigens that are shed into culture medium. Cell surface labeling experiments showed that only the mature MuMTV envelope glycoproteins gp52 and gp36 were exposed on the cell surface, and that gp52 was more abundant than gp36. In cells producing large quantities of MuMTV, expression of gp52 on the cell surface was shown by immunoelectron microscopy to be localized predominantly on the surface of budding virions and not on smooth areas of the cell surface where virus was not budding. The cell surface associated gp36 was found not to be incorporated into budding virions. A few cells in all three cell lines were found to produce only a few or no MuMTV particles and in these cells, unlike in the high virus-producing cells, considerable quantities of gp52 were expressed on the surface membrane. All three cell lines were found to shed large amounts of the MuMTV env precursor polyprotein as well as the mature non-virion-associated glycoprotein, gp52, into the culture medium. The envelope precursor protein (P75env) that was shed into the culture medium was found to differ from the predominant form of the cellular env precursor (Pr70env) in that (1) P75env migrated with an apparent higher molecular weight than Pr70env in SDS gels; (2) Pr70env contained only the core oligosaccharide, whereas P75env contained fucose in addition to the core sugars; (3) two-dimensional gel electrophoretic analysis showed that Pr70env could be resolved into three to four components migrating in the basic region of the isoelectric focussing gel (pH 7-8), whereas P75env was resolved into 9-13 components migrating in a more acidic region of the gel (pH 5-7). The molecular structure of the exfoliated gp52 was found to be similar to that of the gp52 that was incorporated into the virions although the virion-associated gp52 was not the source of the gp52 in the medium. Our quantitative pulse-chase studies suggest that of the two populations of MuMTV env precursors that are present in MuMTV-producing cells, only Pr70env is processed intracellularly to give rise to the mature MuMTV envelope proteins gp52 and gp36.
 ...
PMID:Expression and disposition of the murine mammary tumor virus (MuMTV) envelope gene products by murine mammary tumor cells. 630 86

A single-chain precursor protein for macrophage chemotactic factor was previously reported (Ueda et al, Am J Pathol, 1982, 108:291-298). Apparent chemotactic activity was spontaneously generated in the precursor fraction during a long period of incubation, correlating with the cleavage of the precursor molecule into a two-chain protein. Generation and the limited proteolysis were both inhibited by phenylmethylsulfonyl fluoride (PMSF), a serine protease inhibitor, suggesting the presence and the role of a serine protease in the fraction. A serine protease was actually activated and separated from the precursor fraction with a benzamidine-conjugated cellulose affinity column. The protease was heat-labile, and the substantial molecular weight was 20,000 by gel filtration on a Sephadex G-75 column and 23,000 by SDS-polyacrylamide gel electrophoresis. It hydrolyzed [3H-acetyl casein and also fluorogenic synthetic substrates, butyloxycarbonylphenylalanylserylarginine methylcoumarylamide and butyloxycarbonylisoleucylglutamylglycylarginine methylcuomarylamide, and was inhibited by diisopropylfluorophosphate, PMSF, trasylol, soybean trypsin inhibitor, and tosyllysine chloromethylketone, but not by tosylphenylalanine chloromethylketone, chymostatin, p-chloromercuricbenzoate or ethylenediaminetetraacetate. By incubation of the precursor with the protease, rapid generation of chemotactic activity for macrophages was observed. The fact that the chemotactic factor newly generated in vitro was identical with a macrophage chemotactic factor previously separated from extract of delayed type hypersensitivity skin sites immunologically and physicochemically suggested an essential role of the protease in macrophage chemotactic factor generation in the delayed hypersensitivity skin reaction.
 ...
PMID:The chemical mediation of delayed hypersensitivity skin reactions. IV. Activation of chemotactic factor precursor by a trypsin-like protease in guinea pig plasma. 637 98

In this report we demonstrate that ovine and bovine luteal cells synthesise oxytocin by way of a precursor protein similar to that found in the hypothalamus. Isolated ovine or bovine luteal cells were incubated for up to 12 h with [35S]cysteine. Neurophysin-Sepharose column separation and HPLC of cell extracts demonstrated the presence of [35S]oxytocin. Incorporation of [35S]cysteine was confirmed by performic acid oxidation. Immunoprecipitation of cell extract with anti-rat oxytocin-neurophysin followed by SDS-PAGE yielded 2 radioactive bands of 14 kDa and 11-12 kDa. Immunoprecipitation with anti-oxytocin yielded 1 band at 14 kDa. On SDS-PAGE the 14 kDa band had a similar mobility to rat-hypothalamic oxytocin precursor.
 ...
PMID:Biosynthesis of oxytocin in the corpus luteum. 638 Oct 99

Antibody to poliovirus genome-linked protein VPg, specifically precipitated RNA synthesized in vitro by the poliovirus replicase and host factor in response to poliovirion RNA. A significant amount of the immunoprecipitated RNA was RNAase T1 resistant, sedimented at approximately 2-4 S and was shown to be largely polyuridylic acid. RNAase A digestion or alkali hydrolysis of the immunoprecipitated RNA left [32P]UMP-labeled material which comigrated on SDS-polyacrylamide gels with known VPg-precursor polypeptides. The results presented in this paper suggested that VPg was involved in the host factor-dependent, poliovirus replicase-catalyzed in vitro RNA synthesis, most probably in the form of a larger precursor protein.
 ...
PMID:Antibody to poliovirus genome-linked protein (VPg) precipitates in vitro synthesized RNA attached to VPg-precursor polypeptide(s). 653 2

A putative precursor protein for macrophage-chemotactic factor, which was extracted fro inflammatory skin sites (MCFS-1) (Kambara et al, Am J Pathol 1977, 87:359-374), was found in normal guinea pig plasma and was purified to an apparent homogeneity upon SDS-polyacrylamide gel electrophoresis with a molecular weight of 160,000. This plasma protein was different from complement components of C3 and C5 in terms of molecular weight, functional activity as complements detected by hemolytic assay, and immunologic properties. Although it exhibited the common antigenicity with MCFS-1, it did not show any chemotactic activity for macrophages, However, incubation of this plasma protein at either 4 C for 5 days or 37 C for 1-2 days could generate a chemotactic factor with a molecular weight of approximately 150,000 which was similar to that of MCFS-1. This generation of chemotactic activity was completely prevented by the presence of the serine-type protease inhibitor, phenylmethylsulfonyl fluoride. These data could be well accounted for if we assume that this plasma protein might be a precursor for the macrophage-chemotactic factor found in delayed hypersensitivity skin sites, and that a proteolytic process might be involved in the activation of this precursor.
 ...
PMID:The chemical mediation of delayed hypersensitivity skin reactions: III. Purification and characterization of a precursor protein for macrophage-chemotactic factor in normal guinea pig plasma. 711 65

The precursor protein alpha 1-microglobulin-bikunin was cleaved to the same degree whether expressed in CHO cells or in mutated CHO cells, RPE.40 cells, suggested to lack a functional form of the intracellular protease furin. Thus, alpha 1-microglobulin-bikunin probably is not cleaved in vivo by furin. However, simultaneous overexpression of the precursor and furin in COS, CHO and RPE.40 cells increased the cleavage, suggesting that compartmentalisation and concentrations of protease and precursor are important for the cleavage, besides the in vitro specificity. Expression of alpha 1-microglobulin and bikunin alone gave different protein patterns of SDS-PAGE as compared to expression of the precursor and subsequent cleavage, suggesting that the precursor protein is important for the post-translational handling of alpha 1-microglobulin and bikunin.
 ...
PMID:Processing and secretion of rat alpha 1-microglobulin-bikunin expressed in eukaryotic cell lines. 752 49


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>