SEARCH · PubMed Health

Results for “Chain Migration”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources

PubMed1994

Inefficient processing of human protein C in the mouse mammary gland.

Vitamin K-dependent plasma protein, human Protein C (HPC) has been expressed in transgenic mice, using a 4.2 kb mouse whey acidic protein (WAP) promoter, 9.0 kb HPC gene and 0.4 kb 3' flanking sequences. Expression was mammary gland-specific and the recombinant human Protein C (rHPC) was detected in milk at concentrations of 0.1 to 0.7 mg ml-1. SDS-PAGE revealed that the single, heavy and light chains of rHPC migrated with increased electrophoretic mobility, as compared to HPC. Enzymatic deglycosylation showed that these molecular weight disparities are in part due to differential glycosylation. The substantial increase observed in the amount of single chain protein, as well as the presence of the propeptide attached to 20-30% of rHPC, suggest that mouse mammary epithelial cells are not capable of efficient proteolytic processing of rHPC. The Km of purified rHPC for the S-2366 synthetic substrate was similar to that of plasma-derived HPC, while the specific activity was about 42-77%. Amino acid sequence analyses and low anticoagulant activity of purified rHPC suggest that gamma-carboxylation of rHPC is insufficient. These results show that proteolytic processing and gamma-carboxylation can be limiting events in the overexpression of fully biologically active rHPC in the mouse mammary gland.

Amino Acid Sequence↗

PubMed1987

Cold-stable microtubules from Antarctic fishes contain unique alpha tubulins.

The cytoplasmic microtubules of Antarctic fishes assemble from their tubulin subunits at physiological body temperatures in the range -2 to +2 degrees C. Our objective is to determine the structural features that enhance the assembly of Antarctic fish tubulins at low temperatures. Here we compare the structures of tubulin subunits from three Antarctic fishes (Notothenia gibberifrons, Notothenia coriiceps neglecta, and Chaenocephalus aceratus), from three temperate fishes (the dogfish shark Mustelus canis, the channel catfish Ictalurus punctatus, and the goosefish Lophius americanus), and from a mammal (the cow Bos taurus). When reduced, carboxymethylated, and examined by polyacrylamide gel electrophoresis, multiple alpha chains were observed in tubulins from the Antarctic fishes, the catfish, and the goosefish; dogfish and bovine alpha tubulins migrated as single components on this gel system. Prominent in the Antarctic fish tubulins was an alpha variant that migrated more rapidly than the bovine alpha chain; smaller amounts of a rapidly migrating alpha chain were also present in catfish and goosefish tubulins. The beta tubulins of the fishes, with the exception of the goosefish, resolved into major and minor variants with mobilities similar to those of beta 1 and beta 2 tubulins from bovine brain. Peptide mapping demonstrated that the alpha tubulins of Antarctic fishes were similar in structure, yet differed from the alpha chains of the dogfish and the cow (which, in turn, were similar to each other). In contrast, the beta tubulins from these organisms gave peptide patterns of near identity. Finally, the alpha chains of native tubulins from N. coriiceps neglecta and the cow differed in the sensitivity of their C-terminal domains to digestion by subtilisin. These results demonstrate that the alpha tubulins of Antarctic fishes (but not their beta chains) differ structurally from those of temperate fishes and a mammal.

Animals↗

PubMed1997

Mutations in the heavy chain of cytoplasmic dynein suppress the nudF nuclear migration mutation of Aspergillus nidulans.

To identify proteins that interact directly or indirectly with the NUDF protein, which is required for nuclear migration in Aspergillus nidulans, we initiated a screen for extragenic suppressors of the heat-sensitive nudF6 mutation. Suppressor mutations in at least five genes, designated snfA-snfE, caused improved growth and nuclear migration at high temperatures compared to the nudF6 parent. Two snfC mutations mapped near the nudA gene, which encodes the cytoplasmic dyncin heavy chain, and could be repaired by transformation with wild-type nudA DNA, demonstrating that they are mutations in nudA. The snfC mutations are bypass suppressors of nudF and genetic evidence indicated that NUDA and NUDF act in the same nuclear migration pathway. Taken together, our data suggests that NUDF affects nuclear migration by acting on the dynein motor system.

Aspergillus nidulans↗

PubMed1998

Separation of human globin chains by micellar electrokinetic capillary chromatography.

A new separation method of human globin chains by micellar electrokinetic capillary chromatography (MECC) is described. In this method, a 25 mM phosphate buffer (pH 2.5) containing 7 M urea and 1% (w/v) reduced Triton X-100 buffer system was used. All experiments were performed in a 47 cmx50 microm I.D. uncoated fused-silica capillary. The separation voltage was set at 19 kV. Normal globin chains derived from normal adults and newborns, alpha, beta, delta, Ggamma and Agamma globin chains as well as common variant globin chains were successfully separated within 20 min. High reproducible migration times of globin chains (CVs of intra- and inter-assay were less than 1% and 2% respectively), and quantification of Ggamma and Agamma chains (CVs for intra- and inter-assay were less than 5% and 10%, respectively) were obtained. This new MECC method provides primary information on structural modification of globin chains. It can be an important diagnostic tool in clinical laboratory practice in the field of hemoglobinopathies.

Adult↗

PubMed2006

Intracellular signal transduction for migration and actin remodeling in vascular smooth muscle cells after sphingosylphosphorylcholine stimulation.

Molecular mechanisms underlying migration of vascular smooth muscle cells (VSMCs) toward sphingosylphosphorylcholine (SPC) were analyzed in light of the hypothesis that remodeling of the actin cytoskeleton should be involved. After SPC stimulation, mitogen-activated protein kinases (MAPKs), including p38 MAPK (p38) and p42/44 MAPK (p42/44), were found to be phosphorylated. Migration of cells toward SPC was reduced in the presence of SB-203580, an inhibitor of p38, but not PD-98059, an inhibitor of p42/44. Pertussis toxin (PTX), a Gi protein inhibitor, induced an inhibitory effect on p38 phosphorylation and VSMC migration. Myosin light chain (MLC) phosphorylation occurred after SPC stimulation with or without pretreatment with SB-203580 or PTX. The MLC kinase inhibitor ML-7 and the Rho kinase inhibitor Y-27632 inhibited MLC phosphorylation but only partially inhibited SPC-directed migration. Complete inhibition was achieved with the addition of SB-203580. After SPC stimulation, the actin cytoskeleton formed thick bundles of actin filaments around the periphery of cells, and the cells were surrounded by elongated filopodia, i.e., magunapodia. The peripheral actin bundles consisted of alpha- and beta-actin, but magunapodia consisted exclusively of beta-actin. Such a remodeling of actin was reversed by addition of SB-203580 and PTX, but not ML-7 or Y-27632. Taken together, our biochemical and morphological data confirmed the regulation of actin remodeling and suggest that VSMCs migrate toward SPC, not only by an MLC phosphorylation-dependent pathway, but also by an MLC phosphorylation-independent pathway.

Actins↗

PubMed2004

Receptor tyrosine kinase ErbB4 modulates neuroblast migration and placement in the adult forebrain.

Neural progenitor proliferation, differentiation and migration are continually active in the rostral migratory stream of the adult brain. Here, we show that the receptor tyrosine kinase ErbB4 is expressed prominently by the neuroblasts present in the subventricular zone and the rostral migratory stream. The neuregulins (NRG1-NRG3), which have been identified as ErbB4 ligands, are detected either in the stream or in adjacent regions. Mice deficient in ErbB4 expressed under the control of either the nestin or the hGFAP promoter have altered neuroblast chain organization and migration and deficits in the placement and differentiation of olfactory interneurons. These findings suggest that ErbB4 activation helps to regulate the organization of neural chains that form the rostral migratory stream and influences the differentiation of olfactory interneuronal precursors.

Animals↗

PubMed1991

Changes in glycolipids in human renal-cell carcinoma and their clinical significance.

The expression patterns of glycolipids of human renal-cell carcinoma were studied in primary tumors from 23 cases and 5 metastatic lesions from 4 cases using HPTLC (high-performance thin-layer chromatography). The expression pattern of glycolipids in primary tumors was characteristic of the histological cell type. In granular-cell carcinoma, lactosylceramide (CDH), GM3 and the longer-chain gangliosides (gangliosides migrating more slowly than GM3) increased, although in clear-cell carcinoma, CDH and other glycolipids tended to decrease. Globoside decreased in all cases but one, irrespective of cell type. In metastatic lesions of the clear-cell type, the prominent increase in longer-chain gangliosides was characteristic. Furthermore, the same expression pattern as that of metastastatic lesions was shown in 3 of 14 patients with primary clear-cell carcinoma, all of whom developed metastases soon after radical nephrectomy. These studies indicate that the increased expression of the longer-chain gangliosides in primary tumor is one of the factors associated with high metastatic potential, and also predict early post-operative development of metastasis.

Aged↗

PubMed1985

Conformational studies of myosin phosphorylated by protein kinase C.

Smooth muscle myosin from chicken gizzard is phosphorylated by Ca2+-activated phospholipid-dependent protein kinase, protein kinase C, as well as by Ca2+/calmodulin-dependent kinase, myosin light chain kinase (Endo, T., Naka, M., and Hidaka, H. (1982) Biochem. Biophys. Res. Commun. 105, 942-948). We have now demonstrated the effect of phosphorylation by protein kinase C on the smooth muscle myosin molecule. In glycerol/urea polyacrylamide gel electrophoresis the 20,000-dalton light chain phosphorylated by protein kinase C co-migrated with that phosphorylated by myosin light chain kinase. Moreover, the light chain phosphorylated by both kinases migrated more rapidly than did the light chain phosphorylated by either myosin light chain kinase or protein kinase C alone. Myosin phosphorylated by protein kinase C formed a bent 10 S monomer while that phosphorylated by myosin light chain kinase was an unfolded and extended 6 S monomer in the presence of 0.2 M KCl. In addition, myosin phosphorylated by kinases had a sedimentation velocity of 7.3 S, thereby suggesting that the myosin was partially unfolded. The unfolded myosin was visualized electron microscopically. The fraction in the looped form was higher when for myosin phosphorylated by both kinases higher than for that phosphorylated by light chain kinase alone. Therefore, phosphorylation by protein kinase C does not lead to the change in myosin conformation seen with myosin light chain kinase.

Animals↗

PubMed1983

A proenzyme from chicken plasma similar to human plasma prekallikrein.

We report the isolation of a specific protease zymogen from chicken plasma. The purification procedure involves barium citrate precipitation, ammonium sulfate fractionation, removal of plasminogen and plasmin on lysine-Sepharose, followed by anion and cation exchange, and gel permeation chromatography. Based on quantitative radioimmunoassay the zymogen is present in plasma at a concentration of 160 mg/liter, and it is obtained by our procedure in highly purified form with a yield of 1.4%. The single polypeptide chain contains an NH2-terminal alanine residue. The native molecule migrates in sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 84,000 under reducing conditions. It can be identified as an inactive proenzyme because it has very low amidolytic activity, does not react with the fluorescent active site titrant 4-methyl-lumbelliferyl p-guanidinobenzoate, and does not incorporate radioactive [3H]diisopropylfluorophosphate. It is very susceptible to limited proteolysis which converts it to an active enzyme with trypsin-like specificity. The active enzyme, likewise a single polypeptide chain, migrates as a doublet with apparent molecular weights of 39,000 and 40,000. Its amidolytic activity with synthetic peptide substrates is at least 40-fold higher than that of the proenzyme, it reacts efficiently with 4-methylumbelliferyl p-guanidinobenzoate, and incorporates [3H]diisopropylfluorophosphate while undergoing irreversible inactivation. The enzyme appears to be a reasonably efficient plasminogen activator in zymographic gels, but not in solution. With human high molecular weight kininogen as substrate the enzyme was about 25% as efficient as human plasma kallikrein. It lacks any plasminogen-independent proteolytic activity with other protein substrates, and it hydrolyzes small peptide substrates designed for both human kallikrein and urinary urokinase, respectively. Inhibition studies with peptide chloromethyl ketones indicate enzymatic properties closer to human plasma kallikrein than to the human plasminogen activator urokinase (EC 3.4.21.31). The chicken plasma enzyme and the plasminogen activator from the conditioned media of Rous sarcoma virus-transformed chick embryo fibroblasts treated with tumor promoter are different by criteria of tryptic peptide maps, and amino acid composition and enzymatic specificity. The designations chicken plasma prekallikrein plasminogen proactivator and chicken plasma kallikrein plasminogen activator are proposed for the zymogen and enzyme forms, respectively. Using rabbit antibodies against the proenzyme we developed a solid phase immunoadsorption procedure that allowed us to isolate the protein with an overall yield of 11.4%.

Amino Acids↗

PubMed2003

Enhanced migration and ionic transport through membranes.

The effect of Coulomb forces upon transport enhancement of mobile ions, in the presence of slowly migrating charged polymeric chains, is investigated in a nonequilibrium regime brought about by a semipermeable membrane and a chemical reaction. By means of a numerical solution of the Nernst-Planck-Poisson equations, we predict the size of the effect, the conditions for positive or negative enhancement, and the dependence upon all relevant parameters. The limitations of the description of migration enhancement by an effective diffusion coefficient are also established.

Journal Article↗

PubMed1981

A human b-cell lymphoma synthesizing and expressing surface mu-chain in the absence of detectable light chain.

Lymph node cells obtained from a case of non-Hodgkin's lymphoma, of follicular center cell histology, were seen by immunofluorescence to express immunoglobulin mu heavy chains but no detectable light chain on their surfaces. Antibody specific for determinants expressed only on uncombined mu-chain reacted with these cell surfaces, but not with normal or neoplastic cells expressing surface IgM. Analysis of radioiodinated surface material revealed mu-chains which, without reduction, migrated on SDS-gel electrophoresis as normal mu-chain monomers, and again failed to detect light chains. Lysates of cells incubated with 3H-leucine revealed the synthesis of mu-chains but not of light chains. The labeled mu-chains were not secreted into the culture supernatant, a finding confirmed in parallel cultures by radioimmunoassay. The findings are discussed with particular reference to current concepts of the "mu-chain only" phenotype.

Adult↗

PubMed1993

Large cytoplasmic inclusion body kappa-chain has unusual intrachain disulfide bonding.

The Ig kappa L chain synthesized by the mouse hybridoma line F10 forms large fibrils in the lumen of the endoplasmic reticulum. Despite the formation of these inclusion bodies, free kappa-chain is secreted. Both intracellular and secreted kappa-chains in this line migrate faster on SDS gels; thus, the F10 kappa-chain seems to be more compact than normal Ig L chain. In normal kappa-chain, four cysteine residues form intrachain disulfide bonds and the fifth connects the L chain to the H chain. Although the five cysteine residues of the aberrant kappa-chain are in the normal positions, they display an unusual gel pattern when the intrachain disulfide bonds are opened with 2-ME; that is, the intrachain disulfide bonding pattern of F10 kappa-chain seems to be unusual. It is suggested that the abnormal folding pattern favors fibril formation.

Amino Acid Sequence↗

PubMed2004

To go or not to go: Migration of human mesenchymal progenitor cells stimulated by isoforms of PDGF.

The recruitment of mesenchymal progenitor cells (MPCs) and their subsequent differentiation to osteoblasts is mandatory for bone development, remodeling, and repair. To study the possible involvement of platelet-derived growth factor (PDGF) isoforms, primary human MPCs and osteogenic differentiated progenitor cells (dOB) were examined for chemotaxic response to homodimeric human platelet-derived growth factor AA, -BB, and heterodimeric PDGF-AB. The role of PDGF receptors was addressed by preincubation with PDGF receptor alpha and beta chain specific antibodies. Migration of MPCs, dOB, and primary osteoblasts (OB) was stimulated by the addition of rhPDGF-AA, rhPDGF-BB, and rhPDGF-AB. The effect was highest in MPCs and for rhPDGF-BB, and declining with osteogenic differentiation. Preincubation with the receptor alpha specific antibody decreased the CI to borderline values while pretreatment with the receptor beta specific antibody led to a complete loss of chemotactic response to PDGF isoforms. In control experiments, basal migration values and rhBMP-2 as well as rxBMP-4 induced chemotaxis of MPC were not influenced by the addition of receptor alpha or beta antibodies. Interestingly, without preincubation the parallel exposure of MPC to rhTGF-beta1 instantaneously leads to a selective loss of migratory stimulation by rhPDGF-AA. The chemotactic effect of PDGF isoforms for primary human MPCs and the influence of osteogenic differentiation suggest a functional role for recruitment of MPCs during bone development and remodeling. Moreover, these observations may be useful for novel approaches towards guided tissue regeneration or tissue engineering of bone.

Adult↗

PubMed2000

Supply chain optimization: a practitioner's perspective on the next logistics breakthrough.

The objective of this paper is to profile a practitioner's perspective on supply chain optimization and highlight the critical elements of this potential new logistics breakthrough idea. The introduction will briefly describe the existing distribution network, and business environment. This will include operational statistics, manufacturing software, and hardware configurations. The first segment will cover the critical success factors or foundations elements that are prerequisites for success. The second segment will give you a glimpse of a "working game plan" for successful migration to supply chain optimization. The final segment will briefly profile "bottom-line" benefits to be derived from the use of supply chain optimization as a strategy, tactical tool, and competitive advantage.

Commerce↗

PubMed1979

Polypeptide subunits of dynein 1 from sea urchin sperm flagella.

A high-resolution sodium dodecyl sulfate polyacrylamide gel electrophoresis system has been used to show the presence, in both whole sperm and isolated flagellar axonemes, of eight polypeptides migrating in the 300,000--350,000 molecular weight range characteristic of the heavy chains of dynein ATPase. Previously, only five such chains have been discernible. Extraction of isolated axonemes for 10 min at 4 degrees C with a solution containing 0.6 M NaCl, ph 7, releases a mixture of particles that separate, in sucrose density gradient centrifugation, into a major peak, dynein 1 ATPase, sedimenting at 21S and a minor peak at 12--14S. The polypeptide compositions of these two peaks are different. The dynein 1 peak, which contains most of the protein on the gradient, contains approximately equal quantities of two closely migrating heavy chains, with a small amount of a third, more slowly migrating chain; no other heavy chains appear in this peak. Two groups of smaller polypeptides (three intermediate chains, within the apparent molecular weight range 76,000--122,000 and four newly discovered light chains, within the apparent molecular weight range 14,000--24,000) cosediment with the 21S peak. The heavy chain composition of the 12--14S peak is more complex, all eight heavy chains occurring approximately the same ratios as occur in intact axonemes.

Adenosine Triphosphatases↗

PubMed1967

The stereochemistry of hexahydroprenol, ubiquinone and ergosterol biosynthesis in the mycelium of Aspergillus fumigatus Fresenius.

1. The mycelium of Aspergillus fumigatus has been shown to incorporate mevalonate into squalene, ubiquinone, ergosterol and hexahydroprenol. 2. The (3)H/(14)C ratio in ubiquinone, biosynthesized from [2-(14)C-(4R)-4-(3)H(1)]mevalonate, is the same as in the squalene; essentially no (3)H was incorporated from [2-(14)C-(4S)-4-(3)H(1)]mevalonate, indicating the biosynthesis of biogenetically trans-isoprene units. 3. The (3)H/(14)C ratio for ergosterol (from ;4R-mevalonate') was 3:5, showing that the proton at C-24 is not lost during alkylation of the side chain; it probably migrates to C-25. 4. As (3)H from both mevalonates was incorporated into the hexahydroprenols the biosynthesis of both cis- and trans-isoprene units must occur. 5. The saturated omega- and psi-isoprene units are shown to be biogenetically trans, as are two of the unsaturated residues. 6. The saturated alpha- and unsaturated beta-isoprene residues are both biogenetically cis. 7. An inexplicable loss of approximately half of the olefinic protons from the cis-portion of hexahydroprenol occurs; possible reasons for this loss are discussed. 8. Increase in chain length of the hexahydroprenols is by a cis addition. 9. A biosynthesis of hexahydroprenols by addition of cis-isoprene units to all-trans-geranylgeranyl pyrophosphate, or a dihydro or tetrahydro derivative thereof, is suggested.

Alcohols↗

PubMed1979

Isolation and characterization of 1 alpha-hydroxy-23-carboxytetranorvitamin D: a major metabolite of 1,25-dihydroxyvitamin D3.

The in vivo side-chain oxidation of 1 alpha,25-dihydroxyvitamin D3 was investigated by using a double-label radiotracer technique. Rats dosed with 1 alpha,25-dihydroxy-[3 alpha-3H]vitamin D3 and 1 alpha,25-dihydroxy[26,27-14C]vitamin D3 produced compounds with a high 3H/14C ratio. These compounds were found in sizable quantities in intestine and liver within 3 h after dosing. The major side-chain oxidized metabolite migrated as an acid on DEAE-Sephadex chromatography and contained no 14C. Methyl esterification of this compound with diazomethane proceeded in good yield and rendered the compound more amenable to chromatographic purification. The metabolite was isolated in several steps from rats dosed with 1 microgram of 1 alpha,25-dihydroxy[3 alpha-3H]vitamin D3. The metabolite was obtained in pure form as the methyl ester and was positively identified as 1 alpha,3 beta-dihydroxy-24-nor-9,10-seco-5,7,10(19)cholatrien-23-oic acid. The trivial name calcitroic acid is proposed for this major side-chain oxidized metabolite of 1,25-dihydroxyvitamin D3.

Animals↗

PubMed1979

Comparison of adult, embryonic, and dystrophic myosin heavy chains from chicken muscle by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and peptide mapping.

Chicken myosin heavy chains from adult fast white muscle fibers (both normal and dystrophic), adult slow red fibers, and embryonic presumptive fast white fibers were compared by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and by peptide mapping. The heavy chain of slow red myosin migrated electrophoretically more slowly than the heavy chains of the other myosins and differed markedly from them in its peptide maps. The heavy chain of dystrophic fast white myosin was similar to its normal counterpart by peptide mapping but showed slight differences. The peptide map of the heavy chain of embryonic presumptive fast white myosin had the general features of that of the heavy chain of fast white, not slow red, fibers but contained definite differences from the former. The results are consistent with the existence of a separate gene for the heavy chain of embryonic presumptive fast white myosin.

Animals↗