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Main Protein (main + protein)
Selected AbstractsCharacterization of a Novel Fiber Composite Material for Mechanotransduction Research of Fibrous Connective TissuesADVANCED FUNCTIONAL MATERIALS, Issue 5 2010Hazel R. C. Screen Abstract Mechanotransduction is the fundamental process by which cells detect and respond to their mechanical environment, and is critical for tissue homeostasis. Understanding mechanotransduction mechanisms will provide insights into disease processes and injuries, and may support novel tissue engineering research. Although there has been extensive research in mechanotransduction, many pathways remain unclear, due to the complexity of the signaling mechanisms and loading environments involved. This study describes the development of a novel hydrogel-based fiber composite material for investigating mechanotransduction in fibrous tissues. By encapsulating poly(2-hydroxyethyl methacrylate) rods in a bulk poly(ethylene glycol) matrix, it aims to create a micromechanical environment more representative of that seen in vivo. Results demonstrated that collagen-coated rods enable localized cell attachment, and cells are successfully cultured for one week within the composite. Mechanical analysis of the composite indicates that gross mechanical properties and local strain environments could be manipulated by altering the fabrication process. Allowing diffusion between the rods and surrounding matrix creates an interpenetrating network whereby the relationships between shear and tension are altered. Increasing diffusion enhances the shear bond strength between rods and matrix and the levels of local tension along the rods. Preliminary investigation into fibroblast mechanotransduction illustrates that the fiber composite upregulates collagen I expression, the main protein in fibrous tissues, in response to cyclic tensile strains when compared to less complex 2D and 3D environments. In summary, the ability to create and manipulate a strain environment surrounding the fibers, where combined tensile and shear forces uniquely impact cell functions, is demonstrated. [source] Dietary Lipid Utilization by White Sea Bream (Diplodus sargus) JuvenilesJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2008R. Sá Six experimental diets were formulated to be isoproteic (45% protein) and to contain from 9 to 24% dietary lipid levels (dry matter basis). Fish meal and fish oil were used as the main protein and lipid sources, respectively. At the end of the trial, there were no significant differences (P > 0.05) among groups in fish performance or in whole-body composition. From the results of this trial, it is concluded that, within the range of values tested, increasing dietary lipid levels above 9% has no advantage as it does not promote growth or spare protein for growth purposes. [source] Proteomics of Caenorhabditis elegans over-expressing human , -synuclein analyzed by fluorogenic derivatization,liquid chromatography/tandem mass spectrometry: identification of actin and several ribosomal proteins as negative markers at early Parkinson's disease stagesBIOMEDICAL CHROMATOGRAPHY, Issue 3 2008Tomoko Ichibangase Abstract It has been known that the over-expression of , -synuclein, the main protein of Lewy bodies in Parkinson's disease (PD), leads to neurodegeneration in PD models. In this study, the changes in protein expression between the transgenic over-expressing human , -synuclein wild type (, -synWT) and the control Caenorhabditis elegans were elucidated by fluorogenic derivatization,liquid chromatography/tandem mass spectrometry (FD-LC-MS/MS) proteome analysis, which is a highly selective, sensitive, repeatable and quantitative method for protein identification. Because the , -synuclein wild-type worms showed moderate levels of dopamine loss without overt behavioral abnormalities, it was suggested that the changes in proteins in the , -synWT are related in the sequence of the formation of Lewy bodies. Among more than 400 protein peaks detected, actin and several ribosomal proteins were identified for the first time as negative markers at early PD stages. Actin was suggested to be one of the important targets in the elucidation of the etiology of neuronal diseases such as PD or other synucleinopathies. Copyright © 2007 John Wiley & Sons, Ltd. [source] Bacterial IscU is a well folded and functional single domain proteinFEBS JOURNAL, Issue 11 2004Salvatore Adinolfi Iron,sulfur clusters are widely represented in most organisms, but the mechanism of their formation is not fully understood. Of the two main proteins involved in cluster formation, NifS/IscS and NifU/IscU, only the former has been well studied from a structural point of view. Here we report an extensive structural characterization of Escherichia coli IscU. We show by a variety of physico-chemical techniques that E. coli IscU construct can be expressed to high purity as a monomeric protein, characterized by an ,, fold with high ,-helix content. The high melting temperature and the reversibility of the thermal unfolding curve (as measured by CD spectroscopy) hint at a well ordered stable fold. The excellent dispersion of cross peaks in the 1H- 15N correlation spectrum is consistent with these observations. Monomeric E. coli IscU is able to provide a scaffold for Iron,sulfur cluster assembly, but has no direct interaction with either Fe(II) or Fe(III) ions, suggesting the need of further partners to achieve a stable interaction. [source] First results on a relation between ovarian fluid and egg proteins of Salmo trutta and egg qualityAQUACULTURE RESEARCH, Issue 2 2007Franz Lahnsteiner Abstract By use of sodium dodecyl sulfate polyacrylamide gel electrophoresis, ovarian fluid proteins and main proteins of unfertilized eggs were qualitatively and quantitatively investigated in the brown trout, Salmo trutta, to see whether some of them were correlated with the rate of embryos reaching the eyed embryo stage. In the ovarian fluid, 12 types of proteins in the range of 39,166 kDa were detected whereby three proteins were lipoproteins and two were glycoproteins. Ovarian fluid proteins with a molecular weight of 85, 68, 62 and 39 kDa were negatively correlated with the percentage of eyed stage embryos. The statistical significance of the relations was low in simple and multiple regression models (R2,0.534) indicating that the relations were influenced and superposed by other factors. Therefore, ovarian fluid proteins give only poor information about maturity and quality of eggs. In the eggs, nine major types of proteins in the range of 95,15 kDa were identified. The 95 kDa protein was a lipoprotein, the 85 and the 62 kDa protein were glycoproteins, and the 15 kDa protein was a phosphoprotein. The 95, 85, 77 and 39 kDa protein were positively correlated with embryo survival to the eyed embryo stage. The explanatory effect of the multiple regression model was very high (R2=0.961) indicating that distinct egg proteins are closely related with egg quality. [source] | |||||||||||||