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)

The recent establishment of a role for laminin in mouse lung organogenesis (Schuger et al. 1990a,b, 1991) prompted us to study its expression in the developing lung. Laminin A and B chains were detected in the murine lung from the first hours of development onward. In situ hybridization of mRNA as well as SDS-PAGE studies of lung cells in monoculture indicated that both epithelium and mesenchyme produce complete laminin molecules. Quantitative analysis of the in situ hybridization studies showed a gradual increase in laminin expression during development which was further supported by immunohistochemistry and ELISA. The overall pattern of expression suggested that the effects of laminin in morphogenesis were not restricted to a particular stage of development. Furthermore, the increase in expression during late development supported a role for the molecule in the fetal lung, which was not previously established. We next determined whether the increase in laminin production modulated the behavior of fetal lung cells as compared with their embryonic counterparts. We previously showed that organotypic pattern formation does not occur in cultures of mixed embryonic lung cells unless exogenous laminin is added (Schuger et al., 1990b). Organotypic pattern formation is the result of cell sorting into epithelial and mesenchymal compartments and further rearrangement in a pattern resembling the tissue of origin. In the present study, we demonstrated that organotypic pattern formation occurs spontaneously in cultures of mixed fetal lung cells, which express high laminin levels. Pattern formation was abolished by antibodies to laminin. These studies suggest a correlation between laminin expression and the ability of lung cells in culture to reproduce normal tissue patterns. We conclude that laminin is critical for epithelial-mesenchymal recognition and further morphogenic interaction during both the embryonic and fetal stages of lung development.
Dev Dyn 1992 Sep
PMID:Laminin expression in the mouse lung increases with development and stimulates spontaneous organotypic rearrangement of mixed lung cells. 129 52

The characteristics of outer membrane protein profiles of 41 strains of Campylobacter jejuni from various sources by SDS-PAGE was studied. Seven and nine OMP patterns were differentiated respectively by the presence or absence of six outer membrane protein bands and by the number and size of the molecular weight of the major protein bands. Comparing the OMP patterns of the strains from human with those from animals, the authors inferred that chickens and other animals might be one of the sources for the human infection of Campylobacter jejuni in this district. A comparison between the OMP patterns of the strains from diarrheic children and those from healthy carriers suggested that the pathogenesis of Campylobacter jejuni be possibly associated with the outer membrane proteins. Using the techniques, the authors studied the infection of Campylobacter jejuni in a nursery. The result showed the infection was sporadic and of multi-sources, as evidenced by the multi-patterns of the outer membrane protein profiles. It also indicates that the person-to-person transmission plays a significant role in the infection of Campylobacter jejuni.
Hua Xi Yi Ke Da Xue Xue Bao 1992 Sep
PMID:[Studies of outer membrane protein profiles by SDS-PAGE for Campylobacter jejuni in an epidemiological investigation]. 129 18

D2 dopamine-like receptors have been purified from five bovine brain regions (caudate nucleus, putamen, olfactory tubercle, frontal cortex, cerebellum) and the anterior and neurointermediate lobes of the pituitary gland using a combined ligand-affinity and lectin-affinity chromatography procedure. In all the brain regions except cerebellum and in the neurointermediate lobe of the pituitary gland the purified species appeared as a M(r) 95,000 doublet on SDS-PAGE. In the anterior lobe of the pituitary an additional M(r) 142,000-145,000 species was seen. The M(r) 95,000 species had a low affinity for the lectin wheat germ agglutinin (WGA) whereas the M(r) 142,000-145,000 species had a higher affinity for WGA and additionally showed some affinity for concanavalin A. It is concluded that both the M(r) 95,000 and 142,000-145,000 species are D2 dopamine-like receptors and that the differences between the species are mainly at the oligosaccharide level. Some evidence was also obtained for heterogeneity at the protein level which may correspond to the D2(short) and D2(long) isoforms of these receptors.
Neurochem Int 1992 Sep
PMID:Molecular characterization of D2 dopamine-like receptors from brain and from the pituitary gland. 130 48

Previous studies have shown degradation of cardiac structural proteins and disruption of the sarcolemma as a result of acute myocardial infarction. However, there is no evidence to date on changes in sarcolemmal membrane proteins induced by experimental subacute myocardial infarction. We studied subepicardial layers overlying myocardial infarct 4 days following ligation of the left anterior descending coronary artery in 12 dog hearts. We first demonstrated that this layer provides the anatomic-electrophysiologic substrate for reentrant arrhythmias using activation mapping techniques and histologic correlations. The makeup of membrane proteins was studied using SDS polyacrylamide gel electrophoresis, peptide mapping, and laser densitometry. Sarcolemmal membrane proteins were isolated by ultracentrifugation through a sucrose gradient. We found that a sarcolemmal polypeptide (MW 126,000; n = 12) in the normal tissues has a different mobility than the corresponding protein (MW 124,000; n = 12) of the ischemic tissues although their peptide analysis appeared similar, suggesting that the protein undergoes a post-translational modification. In addition, two proteins (MW 75,000; n = 12 and MW 88,000; n = 12) were present in greater amount in the ischemic than in the control tissues suggesting either acceleration in protein synthesis or slow down of degradation turnover. These results demonstrate that specific changes occur in membrane proteins subjected to ischemic insults which might be responsible for membrane alterations following ischemia and may contribute to the abnormal electrophysiologic properties and arrhythmia seen in vivo at this stage.
Cell Mol Biol 1992 Sep
PMID:Changes in sarcolemmal proteins in subacute myocardial infarction in the dog. 130 6

Desmosmoes were dissolved by incubation at 100 degrees C for 30 minutes in lysis buffer containing 9.5 M urea. SDS-PAGE revealed seven high molecular weight (> 67 kd) bands and some keratins. Seven of these were considered to be major bands. Bands 1 and 2 with M(r) values of 250 kd and 215 kd, called desmoplakins I and II. Polypeptide bands 3, 4a 4b, 5 and 6 had M(r) values of 165kd, 130kd, 115kd, 83kd and 75kd, respectively. 2-2.5mg of Desmoplakin I was obtained by a preparative electrophoresis; the purity reached 93.1%. The isoelectric pH range was between 6.8 and 7.2, and the amino acid compositions displayed a relatively high content of glycine. It was found that McAb Desmoplakin I recognized specifically the 250kd antigenic band by immunoblotting.
Hua Xi Yi Ke Da Xue Xue Bao 1992 Sep
PMID:[Biochemical and immunological characterization of desmosomal proteins]. 130 37

A ligand blotting technique was developed to study the HCG-binding protein from Pseudomonas maltophilia after size separation by SDS-polyacrylamide gel electrophoresis under nonreducing conditions. The separated proteins were transferred to a nitrocellulose sheet, which was subsequently incubated with [125I]iodo HCG, and subjected to determination for radioactivity in gamma-counter. A radioactivity peak equivalent to an M(r) 70000 appeared, which was not observed when the hormone incubation was performed in the presence of an excess of unlabeled HCG. The peak also disappeared when the protein samples were treated with reducing agent, which showed that integrity disulfide bonds of the protein was essential for the protein-hormone interaction. In addition, position of the radioactivity peak which was due to the binding of [125I]iodo HCG to western blots of the HCG-binding protein was corresponding to that of the antibodies against the HCG-binding protein recognizing a 70000 protein on the western blots. These results show that the HCG-binding protein from Pseudomonas maltophilia is an M(r) 70000 protein and that the HCG-binding protein contains at least one disulfide bond essential to its binding activity.
Hua Xi Yi Ke Da Xue Xue Bao 1992 Sep
PMID:[Studies on human chorionic gonadotropin (HCG)-binding protein from Pseudomonas maltophilia by ligand blotting assay]. 130 39

Pollens of Ginkgo biloba L. (G.b.l.p) have been found to be a kind of important allergen which causes pollinosis in Chengdu. The goal of this study is to purify G.b.l.p and to determine the allergenicity and immunogenicity of various fractions. Crude extract was purified by gel filtration with Sephadex G25, then G75. Two elution peaks were observed. On SDS-PAGE, the molecular weights of protein of the 1st peak and the valley were 30-42 kd and 13-18kd, respectively, and that of the 2nd peak was less than 13 kd. 40 patients with allergic rhinitis and/or asthma underwent the skin test with crude extract and various fractions of gel filtration; it revealed that the strongest allergenic activity existed in the 1st peak and there was mild allergenic activity in the 2nd peak. The in vitro allergenic activity and immunogenic activity of various fractions were examined by ELISA inhibition test. It was further confirmed that the allergenic activity and immunogenic activity of the 1st peak were the strongest, and those of the 2nd peak were the lowest. It is suggested that diagnosing reagents can be made satisfactorily by partial purification, i.e. discarding the inactive fractions, since allergenicity exists in various fragments. But fractions of allergen with high IgG immunogenicity should be selected to produce immunotherapy agents so as to enhance the production of blocking antibody and thus improve the therapeutic effect.
Hua Xi Yi Ke Da Xue Xue Bao 1992 Sep
PMID:[Partial purification and analysis of allergenicity, immunogenicity of Ginkgo biloba L. pollen]. 130 47

Treatment of human neutrophils with the peptide f-Met-Leu-Phe (FMLP) results in neutrophil activation concomitant with stimulation of phosphatidylinositol (PtdIns) 3-kinase activity as measured by production of PtdIns-3,4,5-P3 in [32P]orthophosphate labeled cells. Antiphosphotyrosine immunoprecipitates were assayed for PtdIns 3-kinase activity; essentially no activity was present in lysates from either stimulated or unstimulated cells. The 85 kDa regulatory subunit of PtdIns 3-kinase, which normally serves as a substrate for tyrosine kinases, was not detected by SDS-PAGE or Western blot analysis in antiphosphotyrosine immunoprecipitates. In addition, no radioactive band corresponding to PtdIns 3-kinase was observed by SDS-PAGE following antiPtdIns 3-kinase immunoprecipitations. However, immunoprecipitates using polyclonal antibodies against PtdIns 3-kinase showed high PtdIns 3-kinase activity in neutrophil lysates and the 85 kDa subunit of PtdIns 3-kinase was detected in Western blots; no differences in activity were observed in FMLP-stimulated and unstimulated cells. These results suggest that, in contrast to polypeptide growth factor signal transduction systems, the activation of PtdIns 3-kinase by FMLP does not require tyrosine phosphorylation.
FEBS Lett 1992 Sep 14
PMID:Signal transduction in neutrophil activation. Phosphatidylinositol 3-kinase is stimulated without tyrosine phosphorylation. 132 71

An outer-membrane protein (OMP) was isolated from a clinical strain of Bacteroides distasonis. Changes in growth media did not appreciably affect the appearance of this protein in crude outer-membrane preparations examined by SDS-PAGE. However, the proportion of the protein relative to other OMPs was greater in 24-h cultures than in 48-h cultures. The protein could not be readily solubilised by various conventional detergent extraction techniques but treatment of the insoluble material at 100 degrees C with SDS released the protein, as did overnight extraction at 37 degrees C with SDS. This OMP was heat-modifiable, and thus was similar to the OmpA protein of Escherichia coli, with a faster mobility on SDS-PAGE when solubilised at 25 degrees C than at 100 degrees C. The critical temperature for conversion was between 80 degrees C and 90 degrees C. Because of the characteristic heat-modifiability, the protein was called B. distasonis HMP-1 (heat modifiable protein-1). Overnight exposure to EDTA or NaCl at 37 degrees C favoured conversion of the 25 degrees C form to the 100 degrees C form. In intact cells, the protein was labelled by a cell-surface radio-iodination procedure, and thus is at least partially exposed at the cell surface. No reactions between the B. distasonis HMP-1 and antibodies to either E. coli OmpA or E. coli porin were found by Western blot analysis. A B. distasonis OM preparation containing predominantly HMP-1 had pore-forming ability in a liposome assay. This study is the first report of the isolation and characterisation of a heat-modifiable OMP in Bacteroides, and it is the first description of pore-forming activity in a Bacteroides OM fraction.
J Med Microbiol 1992 Sep
PMID:The isolation and characterisation of a major outer-membrane protein from Bacteroides distasonis. 132 60

PC12 cells, a rat pheochromocytoma cell line, has been reported to release norepinephrine in response to extracellular ATP in the presence of extracellular Ca2+. The potency order of ATP analogues was adenosine 5'-O-(3-thiotriphosphate) greater than ATP greater than adenosine 5'-O-(1-thiotriphosphate) = 2-methylthioadenosine 5'-triphosphate (MeSATP) greater than 2'- and 3'-O-(4-benzoyl-benzoyl)ATP (BzATP) greater than ADP greater than 5-adenylylimidodiphosphate. Adenosine 5'-O-(2-thiodiphosphate), beta, gamma-methyleneadenosine 5'-triphosphate, AMP and adenosine were inactive. The ATP action in the absence of extracellular Ca2+, suggests a small but appreciable contribution of intracellular Ca2+ mobilization, for norepinephrine release. However, for some ATP derivatives, like BzATP, almost no contribution of the phospholipase C-Ca2+ pathway is suggested, based on their low activity in inositol phosphates production. To identify the ATP-receptor protein, PC12 cell membranes were photoaffinity-labeled with [32P]BzATP. SDS-PAGE analysis showed that a 53-kDa protein labeling was inhibited by ATP and its derivatives, as well as by P2-antagonists, suramin and reactive blue 2, which inhibit the nucleotide-induced norepinephrine release. The inhibitory activity of the nucleotides was, in parallel with their potency, to induce norepinephrine release. Despite their inability to release norepinephrine, GTP and GTP gamma S inhibited the BzATP labeling, suggesting the participation of a putative G protein in the ATP-receptor-mediated actions. We suggest that the 53-kDa protein on the PC12 cell surface is an ATP receptor, which mediates the norepinephrine release, depending, mainly, on extracellular Ca2+ gating.
Biochim Biophys Acta 1992 Sep 09
PMID:Characterization of ATP receptor which mediates norepinephrine release in PC12 cells. 132 38


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