scholarly journals THE CHLOROPHYLL-PROTEIN COMPLEX

1942 ◽  
Vol 25 (5) ◽  
pp. 755-764 ◽  
Author(s):  
Myer Fishman ◽  
Laurence S. Moyer

1. Reported effects of different conditions on the stability of the purified chlorophyll-protein complex have been confirmed. 2. The electrophoretic behavior of the chlorophyll-protein complex prepared from two unrelated species of plants (Aspidistra elatior and Phaseolus vulgaris) has been investigated and shown to be dissimilar. In M/50 acetate buffer at 25°C, the isoelectric point of the complex from Phaseolus is at pH 4.70, whereas that from Aspidistra is at pH 3.9 (extrapolated). These values fall within the usual range of protein isoelectric points. 3. Treatment with weak acids causes an irreversible denaturation of the protein complex from both species, with a resultant shift in the mobility-pH curves to more basic values. 4. Differences in electrophoretic behavior between the chlorophyll-protein complex and the cytoplasmic proteins of Phaseolus have been demonstrated. The isoelectric point of the latter is at pH 4.22.

2000 ◽  
Vol 122 (29) ◽  
pp. 7130-7131 ◽  
Author(s):  
Sarah J. Luchansky ◽  
Scott J. Nolan ◽  
Anne M. Baranger

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Wen-Yuan Lee ◽  
Hsin-Yi Chen ◽  
Kuan-Chung Chen ◽  
Calvin Yu-Chian Chen

Rheumatoid arthritis (RA) is a chronic inflammatory disease that will affect quality of life and, working efficiency, and produce negative thoughts for patients. Current therapy of RA is treated with disease-modifying antirheumatic drugs (DMARDs). Although most of these treatment methods are effective, most patients still have a pleasant experience either due to poor efficacy or side effects or both. Interleukin-6 receptor (IL6R) is important in the pathogenesis of RA. In this study, we would like to detect the potential candidates which inhibit IL6R against RA from traditional Chinese medicine (TCM). We use TCM compounds from the TCM Database@Taiwan for virtually screening the potential IL6R inhibitors. The TCM candidate compound, calycosin, has potent binding affinity with IL6R protein. The molecular dynamics simulation was employed to validate the stability of interaction in the protein complex with calycosin. The analysis indicates that protein complex with calycosin is more stable. In addition, calycosin is known to be one of the components ofAngelica sinensis, which has been indicated to have an important role in the treatment of rheumatoid arthritis. Therefore, calycosin is a potential candidate as lead compounds for further study in drug development process with IL6R protein against rheumatoid arthritis.


2016 ◽  
Vol 88 (2) ◽  
pp. 751-763 ◽  
Author(s):  
IZAN M. SILVA JUNIOR ◽  
MARIA CLÍCIA S. CASTRO ◽  
DILSON SILVA ◽  
CÉLIA M. CORTEZ

ABSTRACT In this paper, we present the results of a study on the influence of hydrodynamic effects on the surface potentials of the erythrocyte membrane, comparing two different models formulated to simulate the electrophoretic movement of a biological cell: the classical Helmholtz-Smoluchowski model and a model presented by Hsu et al. (1996). This model considers hydrodynamic effects to describe the distribution of the fluid velocity. The electric potential equation was obtained from the non-linear Poisson-Boltzmann equation, considering the spatial distribution of electrical charges fixed in glycocalyx and cytoplasmic proteins, as well as electrolyte charges and ones fixed on the surfaces of lipidic bilayer. Our results show that the Helmholtz-Smoluchowski model is not able to reflect the real forces responsible to the electrophoretic behavior of cell, because it does not take account the hydrodynamic effects of glycocalyx. This charged network that covers cellular surface constitutes a complex physical system whose electromechanical characteristics cannot be neglected. Then, supporting the hypothesis of other authors, we suggest that, in electrophoretic motion analyses of cells, the classical model represents a limiting case of models that take into account hydrodynamic effects to describe the velocity distribution of fluid.


Respuestas ◽  
2017 ◽  
Vol 22 (1) ◽  
pp. 103
Author(s):  
Giovanni Chaves-Bedoya

Resumen Antecedentes: El virus del mosaico de la caña de azúcar, SCMV (Potyviridae) es un miembro de la gran familia de virus de ARN de cadena positiva, sin una estructura CAP en su extremo 5´no traducido (5`UTR), pero con una proteína viral unida al genoma (VPg) y una cola poli A en su extremo 3´UTR. Se ha sugerido que proteínas del hospedero hacen un puente entre las regiones no traducidas virales 5´y 3´ para potenciar la traducción viral. Dado que las regiones no traducidas presentes en los genomas virales contienen elementos involucrados en la regulación de su ciclo replicativo, es importante analizar la interacción entre estas regiones y las proteínas virales o del hospedero para inferir su función. Objetivo: Determinar si existen proteínas del hospedero maíz que pudieran estar interactuando con la región 5´UTR de SCMV. Metodología: La región 5´UTR de SCMV se amplificó por PCR incluyendo la secuencia del promotor T7 en la secuencia del oligo 5´ UTR y se generaron sus transcritos marcados radiactivamente. Los transcritos marcados fueron entrecruzados con extractos proteicos de hojas de maíz sanas e infectadas. Resultados: Los resultados sugieren la presencia de una proteína putativa de interacción del hospedante maíz de aproximadamente 53kDa, con la región 5´UTR de SCMV. Conclusión: Los ensayos de entrecruzamiento, especificidad y estabilidad de los complejos ARN-proteína sugieren que en el hospedante maíz existe al menos una proteína que interactúa con la región 5´ UTR de SCMV.Palabras Clave: Complejo ARN-proteína, entrecruzamiento UV, fracción proteica, Potyvirus, VPg.Abstract Background: Sugarcane mosaic virus is a member of the great family of positive sense RNA viruses, without a CAP structure in its 5´UTR end, but with a viral protein attached to the genome (VPg) and a poli A tail in its 3´UTR end. It has been suggested that some host proteins make a bridge between the untranslated 5´and 3´ regions (UTRs) to enhance the canonical and/or non-canonical virus translation. Since the UTR regions present in the viral genomes have some elements involved in the regulation of their replicative cycle, it is important to analyze the interaction that may occur between these regions and the viral or host proteins to infer regarding its function. Objective: To identify proteins of the host maize that could be interacting with the 5´UTR region of SCMV. Methodology: 5´UTR region of SCMV was amplified by PCR including the sequence of the T7 promoter in the 5´oligo sequence. The transcripts were radioactively labeled. Labeled transcripts were crosslinked with proteins extracts from healthy and infected maize leaves. Results: The results suggest the presence of a 53 kDa putative protein interacting with the 5 ´UTR region of SCMV. Conclusion: Crosslinking essays, specificity and the stability of the RNA-protein complex suggest that in maize host there is at least one protein that interacts with the 5´UTR region of SCMV.Keywords: RNA-Protein complex, UV crosslinking, protein fraction, Potyvirus, VPg


1998 ◽  
Vol 64 (2) ◽  
pp. 405-410 ◽  
Author(s):  
Scot E. Dowd ◽  
Suresh D. Pillai ◽  
Sookyun Wang ◽  
M. Yavuz Corapcioglu

ABSTRACT Many of the factors controlling viral transport and survival within the subsurface are still poorly understood. In order to identify the precise influence of viral isoelectric point on viral adsorption onto aquifer sediment material, we employed five different spherical bacteriophages (MS2, PRD1, Qβ, φX174, and PM2) having differing isoelectric points (pI 3.9, 4.2, 5.3, 6.6, and 7.3 respectively) in laboratory viral transport studies. We employed conventional batch flowthrough columns, as well as a novel continuously recirculating column, in these studies. In a 0.78-m batch flowthrough column, the smaller phages (MS2, φX174, and Qβ), which had similar diameters, exhibited maximum effluent concentration/initial concentration values that correlated exactly with their isoelectric points. In the continuously recirculating column, viral adsorption was negatively correlated with the isoelectric points of the viruses. A model of virus migration in the soil columns was created by using a one-dimensional transport model in which kinetic sorption was used. The data suggest that the isoelectric point of a virus is the predetermining factor controlling viral adsorption within aquifers. The data also suggest that when virus particles are more than 60 nm in diameter, viral dimensions become the overriding factor.


1971 ◽  
Vol 125 (3) ◽  
pp. 703-716 ◽  
Author(s):  
H. Lipke ◽  
T. Geoghegan

1. N-Bromosuccinimide cleaved proteins and pigments from fly puparia, increasing the chitin:protein ratio from 0.5 to 1.5. The product afforded subfractions (ratio 5:1) of molecular weights of 1200 and 1600 devoid of aromatic residues and N-terminal β-alanine, direct aryl links between polysaccharide chains being discounted. 2. The chitin–protein complex decreased in molecular weight when treated with Pronase, which suggested polypeptide bridges within the native chitin micelle. The limit dextrins generated by chitinase were mixtures of unsubstituted dextrins and peptidylated oligosaccharides, with the former predominating. 3. Peptidochitodextrins of similar molecular weight but markedly different solubility were prepared, which were indistinguishable with respect to amino acid, glucosamine, acetyl, X-ray or infrared characteristics. It is suggested that physical interactions contribute to the stability of the integument in addition to the covalent bonds that form during sclerotization.


1995 ◽  
Vol 89 (5) ◽  
pp. 487-495 ◽  
Author(s):  
M. Susan Monteith ◽  
Tao Wang ◽  
Morris J. Brown

1. We have previously reported the relative mRNA and protein level of the long and short splice variants of Gsα (GsαL and GsαS) in human atrium. We have now measured the relative proportions of the serine+ and serine− variants of GsαL and GsαS in human atrium, and assessed, indirectly, whether their differential expression may (i) regulate Gsα phosphorylation, and (ii) be regulated by atrial cyclic AMP levels. 2. The serine+ and serine− variants of GsαL and GsαS were estimated by single nucleotide primer extension in 36 right atrial strips of which half were from β-adrenoceptor-blocked patients. The ratio of serine+ to serine− variants was 0.06 ± 0.12 for GsαL, compared with 8.04 ± 12.16 for GsαS (P < 0.001). 3. Isoelectric points of GsαL and GsαS in the atria of four β-adrenoceptor-blocked and four non-β-adrenoceptor-blocked patients were estimated by two-dimensional gel electrophoresis. Two-dimensional gel analysis gave a consistent pattern with several spots for both GsαL and GsαS; however, the isoelectric points of GsαS were more acid (5.18 ± 0.24) than those of GsαL (5.87 ± 0.17, P < 0.001). 4. No significant difference in either the serine variants or isoelectric point value was observed between β-adrenoceptor-blocked and non-β-adrenoceptor-blocked patients. 5. In conclusion, all four Gsα variants were expressed in human atrium, but GsαL is almost entirely of the serine− form. GsαS has a more acidic isoelectric point than GsαL, indicating a possible post-translational modification. The lack of difference in our results between β-adrenoceptor-blocked and non-β-adrenoceptor-blocked patients suggests indirectly that cyclic AMP is an unlikely candidate for regulating splicing or post-translational modification of Gsα in vivo.


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