Comparative Analysis Of Proteins Research Articles

Identification, N-terminal region sequencing and similarity analysis of differentially expressed proteins inParacoccidioides brasiliensis

Paracoccidioides brasiliensis is the causal agent of paracoccidioidomycosis, which is a systemic mycosis in Latin America. This human pathogen is a dimorphic fungus existing as mycelium (26 degrees C) and in infected tissues as a yeast form (36 degrees C). The in vitro differentiation process is reversible and dependent on temperature shift. In the present study, the total proteins from both forms of P. brasiliensis (isolate Pb01) were analysed by two-dimensional electrophoresis. Differentially expressed proteins were identified. Two of these proteins, PbM46 (mycelium) and PbY20 (yeast), were submitted to automated protein sequencing of their N-terminal regions. The 15 amino acid residue sequence of PbM46, AITKIFALKVYDSSG, is similar to enolases from several sources, and specially those from Saccharomyces cerevisiae (80%) and Candida albicans (67%), when compared to the NR database at NCBI using the BLASTP program. The 34 amino acid residue sequence of PbY20, APKIAIVFYSLYGHIQKLAEAQKKGIEAAGGTAD, could probably represent an allergen protein since it is very similar (90%) to the minor allergen protein of Alternaria alternata and 82% similar to the allergen protein of Cladosporium herbarum. This comparative analysis of proteins from mycelium and yeast forms has allowed the identification and characterization of differentially expressed proteins, probably related to differential gene expression in P. brasiliensis.

Active dissociation of the fluorescent dye Hoechst 33342 from DNA in a living cell: who could do it?

It is assumed that DNA in mammalian cells is a dynamic conformationally unstable system. This instability provides the cell with a mechanism for dissociating a large number of substances that bind tightly but not covalently to DNA. Among these is the fluorescent dye Hoechst 33342, which binds to DNA in the minor groove. We have selected cell lines with a high capability for active dissociation of Hoechst 33342. Comparative protein analysis of these lines by means of two-dimensional (2-D) electrophoresis was performed. Cell and nuclear proteins were analyzed from these and normal strains. A few proteins with significantly changed quantities have been found. The preliminary search of the 2-D database allowed us to identity some known and unknown cellular proteins that could participate in active dissociation of the dye from DNA.

A Comparative Analysis of Proteins in the Scent Gland Secretions of Snakes

A Comparative Analysis of Proteins in the Scent Gland Secretions of Snakes

From the comparative analysis of proteins to knowledge based modeling

From the comparative analysis of proteins to knowledge based modeling

Comparative Analyses of Proteins Extracted by Hot Saline or Released Spontaneously into Outer Membrane Blebs from Field Strains of Brucella ovis and Brucella melitensis

Comparative Analyses of Proteins Extracted by Hot Saline or Released Spontaneously into Outer Membrane Blebs from Field Strains of <i>Brucella ovis</i> and <i>Brucella melitensis</i>

Comparative analysis of proteins induced by heat shock, salinity, and osmotic stress in the nitrogen-fixing cyanobacterium Anabaena sp. strain L-31

Heat, salinity, or osmotic stress influenced protein synthesis in nitrogen-fixing Anabaena sp. strain L-31. Salinity and osmotic stresses were identical and specifically induced 15 polypeptides. Four polypeptides were unique to heat shock, and four other polypeptides were induced under every stress. The results demonstrate a commonality and a stress specificity of protein synthesis regulation.

Comparative analyses of proteins extracted by hot saline or released spontaneously into outer membrane blebs from field strains of Brucella ovis and Brucella melitensis.

Sheep infected with Brucella ovis produce antibody responses to the rough lipopolysaccharide and to proteins present in hot saline (HS) extracts of B. ovis (J. I. Riezu-Boj, I. Moriyón, J. M. Blasco, C. M. Marín, and R. Díaz, J. Clin. Microbiol. 23:938-942, 1986). The distribution and antigenic relatedness of proteins in HS extracts and in outer membrane blebs were established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting for 41 strains of B. ovis and 26 strains of Brucella melitensis of diverse geographic origin. Five major groups of proteins were identified in HS extracts of B. ovis that had been freed of rough lipopolysaccharide: proteins of 43 kilodaltons (kDa), group A (25.5 to 32.0 kDa), group B (21.5 to 22.5 kDa); group C (18.0 to 19.5 kDa), and group D (13.0 to 15.5 kDa). Group A, B, C, and D proteins were also present in blebs. The profiles of proteins in HS extracts or blebs from strains of both Brucella species were very similar. Cross-reactions were demonstrated among HS extracts and blebs of all strains tested in immunoblots performed with an antiserum against the HS extract of a reference strain of B. ovis. Evidence was also provided of an antigenic relationship between group 3 proteins of the outer membrane and some of the proteins in groups A, B, and C. The conservation of these antigens and their immunogenicity in infected animals provide promise that they may serve as components of an effective subcellular vaccine for ovine brucellosis.

The family of glycogen phosphorylases: structure and function.

Glycogen phosphorylase plays a central role in the mobilization of carbohydrate reserves in a wide variety of organisms and tissues. While rabbit muscle phosphorylase remains the most studied and best characterized of phosphorylases, recombinant DNA techniques have led to the recent appearance of primary sequence data for a wide variety of phosphorylase enzymes. The functional properties of rabbit muscle phosphorylases are reviewed and then compared to properties of phosphorylases from other tissues and organisms. Tissue expression patterns and the chromosomal localization of mammalian phosphorylases are described. Differences in functional properties among phosphorylases are related to new structural information. Evolutionary relationships among phosphorylases as afforded by comparative analysis of proteins and gene sequences are discussed.

Introduction of human adenovirus E1A gene into fertilized mouse eggs.

In order to analyze mechanisms through which genes integrated into whole mice influence the expression of mouse genes, we introduced the E1A gene of human adenovirus type 12 into the pronuclei of fertilized mouse eggs. Three (12%) of 26 andthree (6%) of 48 mice that developed from eggs injected with Charon10-gE1A-2 DNA and pSV2-gpt-gEl A DNA, respectively, were found to carry the injected sequences. Multiple copies of the injected DNAs were found integrated into the genomesof these mice. They were arranged mainly in tandem, a head-to-tail form. These mice carrying Charon10-gE1A-2 transmitted the integrated sequences to their progeny. However, the patterns of the transmission were different from mouse to mouse. On the other hand, the mice carrying pSV2-gpt-gE1 A have not so far been confirmed to the capability of transmitting the sequence to their progeny. Comparative analysis of proteins extracted from 6 tissues by two-dimensional gel electrophoresis showed that several proteins were different in their quantities when a mouse carrying Charon10-gE1A-2 was compared to its normal littermate. The MW/pI of these spots were, 27kd/6.4 of lung, and 26kd/5.1, 28kd/5.1, 49kd/5.1, 66kd/5.9, 47kd/6.6, and 24kd/7.1 of pancreatic proteins

Comparative analysis of proteins of Uromyces phaseoli var. typica, U. phaseoli var. vignae, and U. viciae-fabae: polypeptide mapping by two-dimensional electrophoresis

Proteins were extracted from urediospores of the bean rust fungus (Uromyces phaseoli var. typica: two isolates), of the cowpea rust fungus (U. phaseoli var. vignae; two isolates), and of the faba bean rust fungus (U. viciae-fabae; one isolate) and separated by two-dimensional isoelectric focusing – polyacrylamide gel electrophoresis under denaturing conditions. The two isolates of the cowpea rust fungus had identical polypeptide patterns; the two isolates of the bean rust fungus differed by 19 polypeptides. The polypeptide patterns of the bean rust, cowpea rust, and faba bean rust fungi differed markedly from each other. There were 277 polypeptides detected in extracts of the faba bean rust fungus, while more than 335 polypeptides were detected in extracts of each isolate of the other two fungi. While U. phaseoli var. typica and U. phaseoli var. vignae shared 183 polypeptides, U. viciae-fabae had only 149 and 146 polypeptides, respectively, in common with the other two rust fungi. This is consistent with the view that the two varieties of U. phaseoli are more closely related to each other than to U. viciae-fabae. However, when all detected polypeptides were compared, the differences between the two varieties were as extensive as those found between species. It is suggested, therefore, that the designation, by some mycologists of the cowpea rust fungus as a separate species, U. vignae, is correct.

Comparative analysis of proteins labelled with [ 35S]methionine in the liver in vivo and in freshly isolated and short-term-cultured hepatocytes in vitro

[ 35S]Methionine-labelled liver proteins, analysed by one- or two-dimensional gel electrophoresis showed a strikingly similar pattern whether synthesized in vivo or by freshly isolated hepatocytes. In contrast, major qualitative and quantitative differences were observed with the patterns of labelled proteins found in cultured hepatocytes. The changes detectable very early (within 1 h) in culture affected preferentially the synthesis of cytoskeleton proteins (cytokeratins, actin, myosin), which was dramatically increased. Physical factors like cell attachment appear to be responsible for these changes which, however, occurred more rapidly in the presence of serum. Freshly isolated hepatocytes and short-term-cultured cells responded similarly to insulin and glucagon, which respectively increased and decreased the labelling of the whole set of cellular and exported proteins. Glucocorticoids caused either an increase or a decrease in the labelling of several proteins, but the effects were detectable only under chronic exposure of cultured hepatocytes. Based on these results, freshly isolated hepatocytes appear more representative of the liver in vivo than cultured hepatocytes, and therefore seem more suitable for short-term studies. However, cultured hepatocytes can be used for long-term studies since they maintain many specific liver functions and remain hormonally sensitive.

Comparative Protein Analysis of Non-salmonid Fish Rhabdoviruses

SUMMARY On the basis of gel precipitation, reactions with rabbit anti-pike fry rhabdovirus sera, a recent virus isolate (V75/94) from pike fry, and the grass carp rhabdovirus were found to be indistinguishable from pike fry rhabdovirus. The proteins of these viruses were compared to those of spring viraemia of carp virus. In ‘rocket’ immunoelectrophoresis the pike fry rhabdoviruses and the grass carp rhabdovirus showed up to 4 lines with homologous antiserum in which the precipitates formed by the G and M proteins were fused. With this antiserum, spring viraemia of carp virus gave only one precipitation are which was formed by the N protein. All the viruses are very similar to vesicular stomatitis virus with respect to the mol. wt., localization and phosphorylation of structural proteins. In polyacrylamide-SDS slab gels the viruses showed minor differences in the migration of their respective NS proteins.