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Major Protein Component (major + protein_component)
Selected AbstractsPredictive Factors for Pure Steatosis in Alcoholic PatientsALCOHOLISM, Issue 6 2009Sylvie Naveau Background:, Bearing in mind the mechanisms involved in nonalcoholic fatty liver disease, this study aims to verify whether metabolic syndrome or its various individual components are independent predictive factors for steatosis ,10% in alcoholic patients. Methods:, This study included 281 consecutive alcoholic patients with abnormal liver tests and either normal liver histology or steatosis <10% (n = 119) or steatosis ,10% (n = 162). Logistic regression analysis was used to study the relationship between metabolic syndrome components and various risk factors and the presence of steatosis ,10%. We assessed apolipoprotein A1 (ApoA-1) levels, a major protein component of plasma high-density lipoprotein (HDL), rather than HDL-cholesterol levels. Results:, Plasma ApoA-1 levels (p < 0.01), body mass index (BMI) (p < 0.01), and waist circumference (p < 0.05) were significantly higher in patients with steatosis ,10% than in patients with normal liver histology or steatosis <10%. A higher percentage of patients with steatosis ,10% had high blood pressure (p = 0.003) than patients with normal liver histology or steatosis <10%. In the logistic regression, ApoA-1 [odds ratio (OR) = 1.57 (1.10,2.22)], BMI [OR = 1.10 (1.01,1.23)], and high blood pressure [OR = 1.84 (1.10,3.06)] were positively and independently correlated with the presence of steatosis ,10%. In the multivariate regression high blood pressure was independently and positively correlated with steatosis score (r = 0.55 ± 0.26; p < 0.05). On the other hand, when the presence of high blood pressure was the dependent variable, the presence of steatosis ,10% positively and independently correlated with it [OR = 1.82 (1.05,3.15)]. Conclusion:, In alcoholic patients without fibrosis, ApoA-1, BMI, and high blood pressure on the next morning after the admission were predictive of steatosis ,10%. High blood pressure was the only metabolic syndrome component associated with the presence of alcoholic steatosis ,10% and was not correlated with other metabolic syndrome components. These findings suggest that steatosis mechanisms are different in alcoholic and nonalcoholic fatty liver. [source] X-ray crystallographic studies of two transthyretin variants: further insights into amyloidogenesisACTA CRYSTALLOGRAPHICA SECTION D, Issue 3 2005Ricardo M. Neto-Silva Transthyretin (TTR) is a homotetrameric plasma protein that, as a result of a set of not yet fully characterized conformational changes, forms fibrillar aggregates that are the major protein component of amyloid deposits. More than 80 mutations associated with TTR amyloid deposition have been described in the literature. X-ray crystallography was used to elucidate the three-dimensional structure of two important TTR variants: TTR Y78F, an amyloidogenic protein, and TTR R104H, which is associated with a protective effect over the amyloidogenic V30M mutation. The structures of those two TTR variants have been determined in space group P21212 to 1.55 and 1.60,Å resolution, respectively, using molecular-replacement techniques. Detailed analysis of the protein model for TTR Y78F indicates a destabilization of the contacts between the ,-helix and AB loop and the body of the molecule, intimately related to the amyloidogenic nature; contrastingly, in the TTR R104H variant new contacts involving the N-terminal region and His104 are clearly antagonists of amyloid formation. [source] Interleukin-18 secretion and Th1-like cytokine responses in human peripheral blood mononuclear cells under the influence of the toll-like receptor-5 ligand flagellinCELLULAR MICROBIOLOGY, Issue 2 2006Malte Bachmann Summary Flagellin is the major protein component of the flagella from motile bacteria and was identified as the ligand for toll-like receptor (TLR)-5. Whereas its effects on epithelial cells have been studied in detail, activation of human peripheral blood mononuclear cells (PBMC) by flagellin is characterized only partially. By using the recombinant protein of Salmonella muenchen we confirm the proinflammatory nature of flagellin as detected by nuclear factor-,B activation and interleukin (IL)-8 production. Aim of the current study was to elucidate in PBMC effects of flagellin on IL-18 and Th1-like cytokine responses. We report that flagellin in pathophysiologically relevant concentrations augmented release of mature IL-18 by THP-1 monocytes, PBMC, and whole blood stimulated with nigericin or by ATP-mediated P2X7 purinergic receptor activation. Further key functions of the IL-18/IL-12/interferon-, (IFN,) pathway were upregulated by flagellin. Flagellin synergized with IL-12 for production of IFN-, and augmented secretion of interferon-inducible protein-10, a CXC-chemokine that is key to the generation of Th1-type responses. In contrast, neither IL-18-binding protein nor IL-4 was affected. Taken together, the present data demonstrate for the first time that flagellin at concentrations that are detectable in the blood compartment during sepsis efficiently enhances the IL-18/IL-12/IFN, pathway and thus Th1-like cytokine responses in PBMC. [source] Comparative Structural, Emulsifying, and Biological Properties of 2 Major Canola Proteins, Cruciferin and NapinJOURNAL OF FOOD SCIENCE, Issue 3 2008J. Wu ABSTRACT:, Canola is an economically important farm-gate crop in Canada. To further explore the potential of canola protein as value-added food and nutraceutical ingredients, a better understanding of fundamental properties of 2 major canola proteins is necessary. Two major protein components, cruciferin and napin, were isolated from defatted canola meal by Sephacryl S-300 gel filtration chromatography. SDS-PAGE showed that cruciferin consists of more than 10 polypeptides, and noncovalent links are more important than disulphide bonds in stabilizing the structural conformation. Napin consists of 2 polypeptides and is stabilized primarily by disulphide bonds. Purified cruciferin showed 1 major endothermic peak at 91 °C compared with that of 110 °C for napin. Emulsion prepared by cruciferin showed significant higher specific surface area and lower particle size than that of napin. The study indicated that the presence of napin could detrimentally affect the emulsion stability of canola protein isolates. Hydrolysates from cruciferin and napin showed potent angiotensin I-converting enzyme inhibitory activity (IC50: 0.035 and 0.029 mg/mL, respectively), but weaker than that of canola protein isolate hydrolysate (IC50: 0.015 mg/mL). [source] Transmembrane signaling through phospholipase C-, in the developing human prefrontal cortexJOURNAL OF NEUROSCIENCE RESEARCH, Issue 1 2006Iñigo Ruiz de Azúa Abstract To investigate changes in muscarinic receptor-stimulated phospholipase C-, (PLC-,) activity during brain development, we examined the functional coupling of each of the three major protein components of the phosphoinositide system (M1, M3, and M5 muscarinic receptor subtypes; Gq/11 proteins; PLC-,1,4 isoforms) in membrane preparations from post-mortem human prefrontal cerebral cortex collected at several stages of prenatal and postnatal development. In human prenatal brain membranes, PLC was found to be present and could be activated by calcium, but the ability of guanosine-5,-o-3 thiotriphosphate (GTP,S) or carbachol (in the presence of GTP,S) to modulate prenatal PLC-, was significantly weaker than that associated with postnatal PLC-,. Western blot analysis revealed that the levels of G,q/11 did not change significantly during development. In contrast, dramatically higher levels of expression of PLC-,1,4 isoforms and of M1, M3, and M5 muscarinic receptors were detected in the child vs. the fetal brain, a finding that might underlie the observed increased activity of PLC. Thus, inositol phosphate production may be more efficiently regulated by altering the amount of effectors (PLC-,1,4) and receptors (M1,3,5 subtypes) than by altering the level of G,q/11 subunits. These results demonstrate that different PLC isoforms are expressed in the prefrontal cortex of the developing human brain in an age-specific manner, suggesting specific roles not only in synaptic transmission but also in the differentiation and maturation of neurons in the developing brain. © 2006 Wiley-Liss, Inc. [source] | |||||||||||||