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)

Investigations of blood-surface interaction phenomena with polyacrylonitrile-based membrane (AN-69) during hemodialysis are reported. The amount and surface distribution of adhering white blood cells (WBC), and adsorbed proteins (Pt) have been evaluated by image analysis of WBC, spectrophotometry and SDS-polyacrylamide gel electrophoresis of desorbed proteins. The protein contents of the patient's serum have been also investigated by SDS-electrophoresis. Results indicate that the distribution of both WBC, and Pt is non-uniform, and higher (71%, and 79% of the total detected amount, respectively) in the half membrane near the blood inlet (PAN-IN); PAN-IN and PAN-OUT eluates show the same protein bands by electrophoresis. The concentration of the proteins stably adsorbed on the membranes appears not to be related to their concentration in the patient's serum. A relatively strong band at MW = 14,400 in PAN eluates could be interpreted as the presence of lysozyme bound to the AN-69 membranes.
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PMID:Polyacrylonitrile membranes in hemodialysis: blood-surface interactions. 387 Jun 12

Major outer membrane antigens, proteins, and lipopolysaccharides (LPSs), from nontypable Haemophilus influenzae were characterized and examined as targets for complement-dependent human bactericidal antibodies. Outer membranes from two nontypable H. influenzae isolates that caused otitis media and pneumonia (middle ear and transtracheal aspirates) were prepared by shearing organisms in EDTA. These membranes were compared with membranes prepared independently by spheroplasting and lysozyme treatment of whole cells and found to have: similar sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of the proteins; identical densities (rho = 1.22 g/cm3); and minimal d-lactose dehydrogenase activity indicating purity from cytoplasmic membranes. Outer membranes were solubilized in an LPS-disaggregating buffer and proteins were separated from LPS by molecular sieve chromatography. The SDS-PAGE patterns of outer membrane proteins (OMPs) from the two strains differed in the major band although other prominent bands appeared similar in molecular weight. LPS prepared by hot phenol water extraction of each of the strains contained 45% (pneumonia isolate) and 60% (otitis isolate) lipid (wt/wt), 49% and 50% carbohydrate (wt/wt), respectively, and less than 1%, 3-deoxy-manno octulosonic acid. Immunoglobulin M (IgM) purified from normal human serum (NHS) plus complement was bactericidal for both strains. Purified immunoglobulin G (IgG) from NHS killed the middle ear isolate and immune convalescent IgM from the serum of the patient with pneumonia killed his isolate. NHS or convalescent serum were absorbed with OMPs and LPS (0.6-110 micrograms) from each of the strains and immune specific inhibition of bactericidal antibody activity by each antigen was determined. OMPs from the pulmonary isolate inhibited bactericidal antibody activity directed against the isolate in both NHS (1.5 microgram of antigen) and immune serum (0.75 microgram of antigen). OMPs (60 micrograms) from the ear isolate also inhibited bactericidal activity in the respective immune serum. LPSs exhibited minimal inhibition (greater than 110 micrograms). Three human sera (two normal, one immune) were selectively depleted of 80% of antibody activity against OMPs (measured by enzyme-linked immunosorbent assay) by affinity chromatography using OMPs from the pulmonary isolate coupled to a solid phase. These OMP antibody-depleted sera also showed an 88% reduction of bactericidal activity against this strain. Immunopurified antibody against OMPs eluted from the solid phase was bactericidal.
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PMID:Characterization of antigens from nontypable Haemophilus influenzae recognized by human bactericidal antibodies. Role of Haemophilus outer membrane proteins. 387 75

Legionella pneumophila, the etiologic agent of Legionnaires' disease, is phagocytized in an unusual way and multiplies in human mononuclear phagocytes in a novel phagosome. As a first step toward understanding these L. pneumophila-phagocyte interactions, we have studied the envelope of L. pneumophila Philadelphia 1 strain. We isolated cell envelopes by treating whole bacterial cells with lysozyme and EDTA to convert them to spheroplasts, then lysing the spheroplasts osmotically or sonically. We resolved the cell envelopes into two membrane fractions by isopycnic centrifugation. We localized NADH oxidase to the fraction of buoyant density 1.145, which we designated cytoplasmic membrane, and lipopolysaccharide (LPS) to the fraction of density 1.222, which we designated outer membrane. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the L. pneumophila outer membrane contains a single major protein species migrating at 28,000 mol wt; this is the major protein of the bacterium. The cytoplasmic membrane also contains a single major protein species migrating at 65,000 mol wt. Surface iodination of the bacteria and agglutination and immunofluorescence studies with rabbit antibody produced against the purified major outer membrane protein (MOMP) revealed that this protein is exposed at the cell surface. We isolated LPS from L. pneumophila membranes by SDS-EDTA treatment. The pattern obtained by subjecting the LPS to SDS-PAGE and staining the gel with silver nitrate suggests that L. pneumophila LPS might be atypical. We studied patient serologic responses to cell envelope components of L. pneumophila Philadelphia 1, a serogroup 1 organism. Sera from patients with evidence of infection with serogroup 1 L. pneumophila contained large amounts of antibody to this strain. Few of these antibodies recognized the MOMP of L. pneumophila. In contrast, greater than 98% of these antibodies were directed against the LPS. This indicates that LPS is the dominant serogroup antigen and the major antigen responsible for the reactivity of patient sera in the indirect fluorescent antibody assay, currently the principal diagnostic assay for Legionella infection.
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PMID:Isolation and characterization of the cytoplasmic and outer membranes of the Legionnaires' disease bacterium (Legionella pneumophila). 388 79

The third component of complement (C3) is a plasma glycoprotein with a variety of biologic functions in the initiation and maintenance of host response to infectious agents. While the hepatocyte is the primary source of plasma C3, mononuclear phagocytes contribute to the regulation of tissue availability of C3. Lipopolysaccharide (LPS), a constituent of cell walls of gram-negative bacteria, consists of a polysaccharide moiety (core polysaccharide and O antigen) covalently linked to a lipid portion (lipid A). Using metabolic labeling with [35S]methionine, immunoprecipitation, and SDS-polyacrylamide gel electrophoresis, we examined the effects of LPS on synthesis of C3 by human mononuclear phagocytes as well as synthesis of the second component of complement (C2), factor B, lysozyme, and total protein. LPS increased C3 synthesis 5-30-fold without affecting the kinetics of secretion of C3 or the synthesis of C2, lysozyme, or total protein. Factor B synthesis was consistently increased by LPS. Experiments with lipid A-inactivated LPS (alkaline treated), LPS from a polysaccharide mutant strain, and lipid X (a lipid A precursor) indicated that the lipid A portion is the structural element required for this effect. Northern blot analysis demonstrated at least a fivefold increase in C3 mRNA in LPS-treated monolayers, which suggests that the regulation of the increase in C3 synthesis is pretranslational. C2 mRNA and factor B mRNA were increased approximately twofold. The availability of specific gene products in human mononuclear phagocytes that respond to LPS should permit understanding of the molecular regulation of more complex functions of these cells elicited by LPS in which multiple gene products are coordinately expressed.
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PMID:Pretranslational regulation of the synthesis of the third component of complement in human mononuclear phagocytes by the lipid A portion of lipopolysaccharide. 390 Jan 37

The acrA mutation in Escherichia coli led to a substantial increase of the acriflavine-binding capacity of the cell, whereas the related mutations acrB (gyrB) and arcC did not. Metal ions such as Na+, K+, Mg2+, Ca2+ and Al3+ effectively released the bound acriflavine, in proportion to their ionic strengths. The presence of cations, in fact, increased the survival fraction of the cells in the acriflavine-containing medium. Polymyxin B, an antibiotic which binds to membrane phospholipid, competed with acriflavine for binding sites. Cell wall digestion by treatment with lysozyme and EDTA slightly decreased the acriflavine-binding capacity. Almost no difference was observed in acriflavine-binding capacity between intact cells and cells from which lipopolysaccharide has been extracted (46.9% removed from the acrA cells and 47.4% from the acrA+ cells). Acriflavine bound to the cells was most effectively extracted by ethanol containing 1% HCl or by 2% (w/v) SDS. The difference in the acriflavine-binding capacity between the acrA and acrA+ cells was also observed in the spheroplasts. These facts indicate a relationship between the acrA gene product and the acriflavine-binding capacity of the cells.
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PMID:Acriflavine-binding capacity controlled by the acrA gene of Escherichia coli. 390 Feb 82

Cell walls (LOG walls) were isolated from cultures of Streptococcus faecalis ATCC 9790 in the exponential phase of growth. These walls were either allowed to undergo autolytic dissolution (in the presence or absence of trypsin) or wall autolysis was inactivated with sodium dodecylsulfate (SDS walls). Inactivated walls were treated either with lysozyme or with isolated, partially purified S. faecalis autolysin. During wall lysis, samples were removed, negatively stained with phosphotungstate, and examined in the electron microscope. Both lysozyme and isolated autolysin appeared to act over the entire surface of SDS walls. After partial dissolution, a fibrous network over the surface was revealed. Lysozyme digestion revealed the presence of prominent, highly-contrasted equatorial and subequatorial bands around the walls. After trichloroacetic acid extraction, the bands were seen less frequently and less distinctly in the partially lysozyme digested walls, suggesting that the bands contained nonpeptidoglycan polymers. In the absence of trypsin (which activates a latent form of the autolysin), autolysis of LOG walls appeared to start at the equatorial bands and to proceed back towards the apex of the coccus. Ribbons of wall material coming off the wide edge of the nearly hemispherical wall fragments were observed. Activation of latent autolysis resulted in lytic action over the entire wall surface. The results are consistent with the previously postulated location of active autolysin at the areas of new wall synthesis and the random location of latent autolysin in LOG walls.
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PMID:Autolytic enzyme system of Streptococcus faecalis. IV. Electron microscopic observations of autolysin and lysozyme action. 497 30

Polyamines are natural constituents of most living organisms. However, their function in normal or pathological conditions is not fully understood. We have investigated in vitro effects of polyamines on characteristic properties of isolated renal brush-border membrane vesicles in order to determine whether polyamines have a regulatory role in membrane transport processes. The polyamines putrescine, spermidine and spermine were found to stimulate D-glucose uptake. Diffusional L-glucose uptake was not altered, indicating that the polyamines affected the active transport of D-glucose, rather than inducing nonspecific changes in membrane lipid properties. The amiloride-sensitive Na+ /H + exchange was slightly inhibited by polyamines while Mg2+ -ATPase activity was stimulated. The polyamine effects could not be explained solely by the polycationic properties of these agents, since polycationic polypeptides had an opposite effect. For example, lysozyme was found to inhibit D-glucose transport. Spermine was incorporated into the trichloroacetic acid-insoluble fraction of brush-border membrane proteins. Results indicated that this incorporation process consisted of at least two components: a Ca2+ -independent component and a Ca2+ -dependent component, possibly as a result of transglutaminase activity which was present in the isolated renal brush-border membranes. By using SDS-polyacrylamide gel electrophoresis in conjunction with fluorography, [3H]spermine was shown to be incorporated into several brush-border membrane proteins, mainly the 57 kDa, 74 kDa, 100 kDa, a heavy molecular weight band (greater than 200 kDa) and a low molecular weight band (less than 10 kDa). Our results suggest that the polyamine effects on membrane function may be due to a covalent modification of membrane proteins, possibly via a transglutaminase-mediated incorporation of polyamines or to the crosslinking of membrane proteins.
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PMID:Polyamines stimulate D-glucose transport in isolated renal brush-border membrane vesicles. 614 64

A human neutrophil protease, initially termed neutral peptide-generating protease, has been shown to cleave angiotensin II directly from angiotensinogen and has been identified as leukocyte cathepsin G. When purified neutrophils were disrupted by nitrogen cavitation and fractionated by differential centrifugation, 44 and 24% of the angiotensin II-generating activity was in the lysosomal and undisrupted cell fractions, respectively. Cytochalasin B-treated human neutrophils stimulated with N-formyl-L-methionyl-L-leucyl-L-phenylalanine released beta-glucuronidase, lysozyme, and angiotensin II-generating protease in a dose-dependent fashion, consistent with localization of this protease to the neutrophil granule. Individually purified angiotensin II-generating protease and cathepsin G had similar proteolytic and esterolytic activity for angiotensinogen and N-benzoyl-L-tyrosine ethyl ester on a weight basis, exhibited identical mobilities by SDS-gradient polyacrylamide gel electrophoresis and pH 4.3 disc-gel electrophoresis, and gave precipitin lines of antigenic identity on Ouchterlony analysis with goat antibody to the angiotensin II-generating protease. Thus, the angiotensin II-generating protease of human neutrophils has been identified as cathepsin G on the basis of subcellular localization, substrate specificity, physicochemical characteristics, and antigenic identity.
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PMID:Identification of a human neutrophil angiotension II-generating protease as cathepsin G. 617 48

To evaluate the role of NK cell granules in the lytic activity of NK cells, cytoplasmic granules of rat NK tumors were purified by centrifugation of the cell homogenates in a Percoll gradient. Analysis of such gradients showed a band of light-scattering material near the bottom of the tube; assay of gradient fractions for lytic activity against SRBC showed a potent lytic activity giving a sharp peak in this region. Complete lysis of SRBC was achieved with less than 1 microgram/ml protein of the most active fractions. Examination in the electron microscope showed that a pool of fractions containing lytic activity consisted of pure cytoplasmic granules showing similar morphology to those found in the LGL tumors. The lytic band was associated with a peak in the activity of four different lysosomal enzymes. Analysis of Percoll gradient fractions showed that marker enzymes for mitochondria, plasma membrane, and cytosol were well separated from this activity peak. Analysis of the Percoll gradient fractions by SDS gel electrophoresis showed that this granule fraction was free of contamination of proteins from other parts of the gradient. The granules contained major protein bands of 62, 58, 30, 29, and 28 kilodaltons. In addition to protein, the purified granule fractions contain hexose and uronic acid, but no nucleic acids or phospholipids were detected in chemical assays. Major amounts of chymotryptic, tryptic, and elastase activities were not present, nor were peroxidase or lysozyme activities detectable in substantial amounts. These data show that NK tumor cell cytoplasmic granules contain a potent lytic activity and have biochemical properties that distinguish them from granules present in granulocytes and mast cells.
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PMID:Purification and properties of cytoplasmic granules from cytotoxic rat LGL tumors. 637 25

Exposure of serum-susceptible Escherichia coli strains to lethal concns of lysozyme-free human serum resulted in stable binding of complement components to the outer membrane (OM), but not to the cytoplasmic membrane (CM). The short prekilling phase of the reaction was accompanied by binding of C3b; loss of viability was immediately preceeded by stable deposition onto the OM of the component proteins of the membrane attack complex. During the early stages of the active killing phase, bound monomeric C9 could be resolved into two distinct bands on SDS-polyacrylamide gels. Serum exposure lead to a progressive loss of CM recoverability, which appeared to result from partial degradation of CM phospholipids. In contrast, exposure of a resistant E, coli strain to human serum resulted in little change in the membrane profile and very little stable deposition of terminal complement components onto the OM.
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PMID:Interaction of human complement proteins with serum-sensitive and serum-resistant strains of Escherichia coli. 637 18


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