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

Protein synthesis of human placenta from cesarean section was analyzed by SDS gel electrophoresis using full term cell culture system. The qualitative pattern of cytoskeletal proteins before and after culture was also examined. After trypsinization, cytotrophoblasts were cultured for 20 days in the humidified incubator of 5% CO2 in 95% air. The confluency was obtained in 10 days after inoculation. The pattern of SDS-PAGE showed several protein bands including actin (43,000 Da) and desmin (55,000 Da) as major constituents of 12 and 20 day cultures. The significant differences between band appearances in samples before and after culturing were noted. The present results indicated that myosin may not be synthesized in high content, differing from previous observations. Cytoskeletal protein production seemed to be markedly enhanced in the cultured system.
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PMID:The protein synthesis of human full term placenta cell in monolayer culture system. 239 55

The localization of DNA and the distribution of the cytoskeletal proteins actin, myosin and tubulin in spermatozoa of Libinia emarginata L. were the aims of this study. DAPI, a highly reactive DNA-binding agent, revealed fluorescent staining within nucleocytoplasmic compartments around the acrosome and in the radial processes extending from the central region of the spermatozoa. The sites of DAPI-DNA staining corresponded to the position of the branched chromatin fibers revealed by electron microscopy. Antisera to myosin, actin, and tubulin revealed staining at different nucleocytoplasmic sites and in radial processes of the spermatozoa. Myosin was present at the base of each of three radial extensions, whereas actin appeared throughout the nucleocytoplasmic compartment and in the radial extensions. Actin fluorescence corresponded to the 6 nm thick filaments visualized by electron microscopy forming the core of the radial processes. Although tubulin was observed throughout the cell and within radial processes by immunofluorescence staining, intact microtubules were not revealed by electron microscopy. However, SDS PAGE comparisons between Libinia sperm extracts and dogfish brain showed small amounts of protein that comigrate with alpha and beta tubulin. These results demonstrate the existence of contractile proteins (myosin, actin) and tubulin within the DNA-containing nucleocytoplasmic compartments of Libinia sperm.
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PMID:Contractile proteins (actin, myosin) and tubulin are revealed within DNA-containing nucleocytoplasm in mature spermatozoa of Libinia emarginata L. 242 42

Monoclonal antibodies (MAb) raised to intact Streptococcus mutans P-4 cells (serotype e) were used to demonstrate the presence of shared antigenic determinant(s) between S. mutans BHT (serotype b) cell membranes and human heart tissue. MAb binding to both BHT membrane and human heart tissue was demonstrated by ELISA. Common antigens were identified by immunoblot analysis following separation of BHT membrane components and human heart antigens by SDS-PAGE. MAb 22C4 recognized three polypeptides from the BHT membrane preparation, having molecular masses of 42, 56 and 85 kDa. MAb 22C4 also recognized an 85 kDa component and a 200 kDa component from human heart tissue. MAb D159 was specific for a single 82 kDa polypeptide in BHT membrane, and also bound to two high molecular mass components in human heart (165 and 200 kDa). When both MAb D159 and 22C4 were first absorbed with S. mutans P-4 cells, subsequent reactivity to the aforementioned BHT membrane components was inhibited, indicating that these cross-reactive components are found in S. mutans P-4 as well as in S. mutans BHT micro-organisms. Competitive binding analysis showed that both MAb D159 and MAb 22C4 bound to myosin, indicating that S. mutans BHT membrane, human heart tissue and myosin share at least one immunodeterminant. This indicates that myosin could be the cross-reactive tissue component in human heart.
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PMID:Demonstration of shared antigenic determinants between Streptococcus mutans BHT cell membrane, human heart tissue and myosin using monoclonal antibodies to S. mutans. 244 99

Decay-accelerating factor (DAF) is a constitutively expressed plasma membrane glycoprotein on blood cells and endothelium that inhibits cell surface C3/C5 convertase formation, thus inhibiting complement activation and protecting cells from lysis by the terminal complement components. Using monoclonal anti-DAF antibodies in conjunction with anti-smooth muscle cell (SMC)-specific myosin antibodies, it was found by immunohistochemistry that vascular SMC in advanced human carotid atherosclerotic lesions express DAF antigen. The percentage of DAF-positive SMC ranged from 20 to 60% between different patient samples and SMC DAF expression was limited to SMC in the lesion proper. Normal arterial wall SMC exhibited no DAF-specific immunostaining. Essentially 100% of passaged cultured vascular SMC derived from normal human uterine artery, or from umbilical vein, expressed DAF as assessed by immunocytochemistry. A 68-kD band was observed on SDS-PAGE autoradiograms of DAF-immunoprecipitated radiolabeled cultured SMC extracts. Sensitization of rabbit erythrocytes with DAF-containing SMC extracts conferred protection against complement-mediated hemolysis in normal human serum and the protective effect could be reversed by treatment with anti-DAF antibodies. We conclude that DAF is induced on vascular SMC during atherogenesis and in culture.
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PMID:Decay-accelerating factor is expressed on vascular smooth muscle cells in human atherosclerotic lesions. 247 72

SDS-polyacrylamide gel electrophoresis was used to study the effects of the thiol inhibitor monobromobimane (MB), EDTA, and prostaglandin E1 (PGE1) on the formation and composition of the platelet cytoskeletal core (Triton-insoluble residue) and its association with glycoprotein (GP) IIIa. Stimulation or aggregation of platelets in response to ADP or thrombin increased the amount of Triton-insoluble myosin. Aggregation resulted in incorporation of [125I]GP IIIa and a new band at about 210 kDa into the cytoskeletal core. EDTA and PGE1 caused little disaggregation of platelets that were aggregated in PRP with ADP and that had secreted the contents of their granules. In contrast to EDTA, PGE1 decreased the amount of Triton-insoluble residue and its association with GP IIIa. MB added after ADP-induced aggregation caused an increase in the amount of cytoskeletal core despite marked disaggregation and a substantial decrease in core-associated GP IIIa. With aspirin-treated platelets that had not secreted, EDTA, PGE1, and MB all caused disaggregation and loss of cytoskeletal GP IIIa. MB diminished, but did not reverse, thrombin-induced aggregation of washed platelets and arrested GP IIIa incorporation into the cytoskeletal core. Concanavalin A (Con A) cross-links glycoproteins on a single platelet and induces incorporation of GP IIIa into the Triton-insoluble residue in the absence of platelet aggregation. This induction was not inhibited by MB, although this reagent, as well as aspirin, inhibited Con A-induced secretion. Since GP IIIa incorporation caused by ADP-induced aggregation differs from that caused by Con A in its susceptibility to MB, it seems unlikely that thiol groups are directly involved in the association of GP IIIa with the cytoskeletal core.
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PMID:Effect of the thiol group inhibitor monobromobimane and other inhibitors on the composition of the platelet cytoskeletal core and its association with glycoprotein IIIa. 249 43

Measurements of cross-bridge attachment to actin in myofibrils during ATP hydrolysis require prior fixation of myofibrils to prevent their contraction. The optimal cross-linking of myofibrils was achieved by using 10 mM carbodiimide (EDC) under rigor conditions and at 4 degrees C. The fixed myofibrils had elevated MgATPase activity (150%) and could not contract. As judged by chymotryptic digestions and subsequent SDS gel electrophoresis analysis, less than 25% of myosin heads were cross-linked in these myofibrils. The isolated, un-cross-linked myosin heads showed pH-dependent Ca2+- and EDTA(K+)-ATPase activities similar to those of standard intact S-1. For measurements of myosin binding to actin, the modified myofibrils were digested with trypsin at a weight ratio of 1:50 under rigor, relaxed, and active-state conditions. Aliquots of tryptic digestion reactions were then cleaved with chymotrypsin to yield isolated myosin heads and their fragments. Analysis of the decay of myosin heavy-chain bands on SDS gels yielded the rates of myosin cleavage under all conditions and enabled the measurements of actomyosin binding in myofibrils in the presence of MgATP. Using this approach, we detected rigorlike binding of 25 +/- 6% of myosin heads to actin in myofibrils during ATP hydrolysis.
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PMID:Binding of myosin to actin in myofibrils during ATP hydrolysis. 252 35

The morphology and function of actin in cultured bovine retinal pigment epithelial (RPE) cells were studied. Filamentous actin was identified with a fluorescent mushroom toxin, nitrobenzoxadiazole (NBD)-phallacidin, specific for actin. Dark-field microscopy of cultured RPE cells revealed numerous pigment granules; fluorescent microscopy identified scattered lipofuscin granules. One-dimensional SDS polyacrylamide gel electrophoresis of urea-soluble proteins extracted from RPE cells showed a 46,000-dalton protein band which comigrated with authentic muscle actin. Densitometric scanning showed that this protein band comprised 7.6% of the total urea-soluble proteins. An actin-activated skeletal-muscle myosin Mg-ATPase assay, using skeletal-muscle heavy meromyosin as enzyme and [gamma-32P]-ATP as substrate, demonstrated functional actin in RPE cell extracts after DEAE-cellulose anion exchange chromatography. The actin-containing protein fractions were eluted at ionic strengths between 0.19 and 0.36 M KCl. The activation of myosin ATPase by actin in RPE cells provides a molecular basis for the phagocytic activity which is important in maintaining the integrity of retinal photoreceptor cells.
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PMID:Activation of Mg-ATPase of skeletal-muscle myosin by bovine retinal pigment epithelial actin. 253 75

Myosin was purified from bovine erythrocytes by chromatography on DEAE-cellulose, Sepharose CL-4B, hydroxylapatite, and DEAE-5PW. The yield was about 200 micrograms/L of packed cells. From SDS-polyacrylamide gels, the purity was estimated to be greater than 95%. The bovine erythrocyte myosin is composed of heavy chains of 200 kDa and light chains of 20 and 17 kDa, in a molar stoichiometry of 1. Myosin was also purified from human erythrocytes by the same method. The molecular weights of two light chains were 26K and 19.5K which confirmed the earlier reports [Fowler, V. M., Davis, J. Q., & Bennet, V. (1985) J. Cell Biol. 100, 47-55; Wong, A. J., Kiehart, D. P., & Pollard, T.D. (1985) J. Biol. Chem. 260, 46-49]. Phosphorylation by gizzard myosin light chain kinase, to a level of 1 mol of phosphate/mol of 20-kDa light chain, increased actin-activated ATPase, and the extent of activation was dependent on the MgCl2 concentration. Both Ca2+-ATPase and Mg2+-ATPase activities were dependent on KCl concentration and markedly decreased below 0.3 M KCl. Mg2+-ATPase of phosphorylated myosin, while more resistant to decreasing ionic strength, was also decreased below 0.2 M KCl. These results are similar to those obtained with smooth muscle myosin and suggest that the 10S-6S transition occurs. In confirmation of this, gel filtration, viscosity, and electron microscopy (rotary shadowing) show that erythrocyte myosin forms extended and folded conformations in high and low salt, respectively. It is proposed that each conformation is characterized by distinct enzymatic properties.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Correlation of enzymatic properties and conformation of bovine erythrocyte myosin. 254 59

Previous studies have shown that smooth muscle myosin consists of two heavy chains (MHCs) of unequal molecular weight; however, it is not clear whether there are intermuscle, inter- and intraspecies differences in the MHCs. The purpose of these experiments was to quantitatively and qualitatively compare MHCs in different smooth muscles. Extracts of bovine aorta (BAo), dog saphenous vein (dSV) and femoral artery (dFA), and rat aorta (rAo), femoral artery (rFA), carotid artery (rCA), ileum (rGI) and uterus (rUt) were electrophoresed on 5% polyacrylamide-1% SDS gels. All tissues exhibited two MHCs with molecular weights of 207,000 (MHC1) and 204,000 (MHC2) daltons. In all cases the proportion of total MHC made up by MHC1 was greater than that by MHC2. Based on their relative proportions (MHC1:MHC2), the tissues fell into one of three groups: (1) 55:45 - rAo, rCA, dFA; (2) 60:40 - dSV, BAo, rGI; and (3) 65:35 - rUt, rFA. Group 1 differed significantly from group 3 in the proportion of each MHC. One dimensional peptide maps indicated that BAo, dSV and dFA were similar while subtle differences existed between rUt and rAo. Differences between rUt and rAo were also observed in their cross-reactivity to a monoclonal antibody to smooth muscle MHC, confirming the differences seen on peptide maps. These results indicate that there are intertissue and inter- and intraspecies differences in smooth muscle MHCs. The significance of these differences to muscle function remains to be determined.
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PMID:Quantitative and qualitative heterogeneity in smooth muscle myosin heavy chains. 258 23

We prepared monoclonal antibodies directed against chicken gizzard myosin light chain kinase (MLCK) and used them to study the contractile system of aortic smooth muscle. One monoclonal antibody, MM13, dose dependently inhibited actomyosin superprecipitation of bovine aortic smooth muscle, in accord with the suppression of 20 kDa myosin light chain phosphorylation by endogenous kinase. Immunoblotting analysis demonstrated that MM13 cross-reacted with the 150,000 Mr peptide of bovine aortic actomyosin preparation. The bovine aortic MLCK was purified approximately 2,400-fold to apparent homogeneity by three steps of column chromatography. The purified enzyme has a molecular weight of 150,000 and a slower mobility than chicken gizzard MLCK (130,000 Mr), as determined by SDS-polyacrylamide gel electrophoresis. MM13 also cross-reacted with purified bovine aortic MLCK and inhibited the kinase activity, in vitro. We interpret these findings to mean that binding of the anti-gizzard MLCK monoclonal antibody directly to aortic smooth muscle MLCK (150,000 Mr) decreases the phosphorylation of the 20 kDa myosin light chain, thus suppressing the aortic smooth muscle myosin-actin interaction.
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PMID:Anti-gizzard MLCK monoclonal antibody MM13 inhibits superprecipitation and phosphorylation of bovine aortic smooth muscle actomyosin. 260 3


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