scholarly journals Evidence of an endogenous lectin receptor in seeds of the legume Cratylia floribunda

2002 ◽  
Vol 14 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Márcio Viana Ramos ◽  
Liezelotte Rezende Bomfim ◽  
Bandeira ◽  
Henri Debray
Keyword(s):  
Western Blot ◽  
Affinity Chromatography ◽  
Real Time ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein Fractions ◽  
Carbohydrate Binding ◽  
Lectin Activity ◽  
Lectin Receptor ◽  
Endogenous Lectin ◽  
Time Interaction

Cratylia floribunda seeds were ground and the clean crude saline extract was fractionated into albumin, globulin, prolamin, acidic and basic glutelin protein fractions. These protein fractions were examined for the presence of an endogenous lectin receptor by SDS-polyacrylamide gel electrophoresis, western blot, affinity chromatography on a Sepharose 4B-Cratylia floribunda (CFL) lectin column and kinetic analysis in real time by surface plasmon resonance (SPR). Prolamin was the richest protein fraction although very poor in haemagglutinating activity. Basic glutelin was far the less interesting fraction for lectin activity and protein content, even though this fraction contains considerable amounts of carbohydrates. Lectin was present in all protein fractions as estimated by haemagglutinating assays but basic glutelins were almost devoid of lectin activity. Except for prolamins, protein bands were detected by SDS-PAGE in all other fractions. Western blot using digoxigenin labelled Con A revealed a single band in the albumin, globulin, acidic and basic glutelin fractions, which specifically interacted with ConA. This band migrated exactly at the same position in such fractions and seemed to be more important in the globulins. Affinity chromatography of the protein fractions on a Sepharose-CFL column yielded a peak, which was only recovered after elution with acidic buffered solution or with an alpha-D-mannose solution and the monosaccharide was recognized by the lectin. These results were fully corroborated by real time interaction of immobilized CFL with the different soluble protein fractions suggesting the presence of a lectin receptor within albumins, globulins and basic glutelins. As a whole, the results suggest that the lectin from Cratylia floribunda recognizes a soluble endogenous glycosylated receptor through an interaction mediated by its carbohydrate-binding site.

scholarly journals Adaptive Model for Biofeedback Data Flows Management in the Design of Interactive Immersive Environments

2021 ◽  
Vol 11 (11) ◽  
pp. 5067
Author(s):  
Paulo Veloso Gomes ◽  
António Marques ◽  
João Donga ◽  
Catarina Sá ◽  
António Correia ◽  
...  
Keyword(s):  
Real Time ◽  
Emotional State ◽  
Adaptive Model ◽  
Multimodal Data ◽  
The Real ◽  
Time Interaction ◽  
Data Flows ◽  
Immersive Systems ◽  
Immersive Environment ◽  
The Relationship

The interactivity of an immersive environment comes up from the relationship that is established between the user and the system. This relationship results in a set of data exchanges between human and technological actors. The real-time biofeedback devices allow to collect in real time the biodata generated by the user during the exhibition. The analysis, processing and conversion of these biodata into multimodal data allows to relate the stimuli with the emotions they trigger. This work describes an adaptive model for biofeedback data flows management used in the design of interactive immersive systems. The use of an affective algorithm allows to identify the types of emotions felt by the user and the respective intensities. The mapping between stimuli and emotions creates a set of biodata that can be used as elements of interaction that will readjust the stimuli generated by the system. The real-time interaction generated by the evolution of the user’s emotional state and the stimuli generated by the system allows him to adapt attitudes and behaviors to the situations he faces.

scholarly journals KLK11 promotes the activation of mTOR and protein synthesis to facilitate cardiac hypertrophy

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yi Wang ◽  
Hongjuan Liao ◽  
Yueheng Wang ◽  
Jinlin Zhou ◽  
Feng Wang ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Western Blot ◽  
Real Time ◽  
Real Time Pcr ◽  
Mtor Signaling ◽  
Heart Weight ◽  
Cardiomyocyte Hypertrophy ◽  
Quantitative Real Time Pcr

Abstract Background Cardiovascular diseases have become the leading cause of death worldwide, and cardiac hypertrophy is the core mechanism underlying cardiac defect and heart failure. However, the underlying mechanisms of cardiac hypertrophy are not fully understood. Here we investigated the roles of Kallikrein 11 (KLK11) in cardiac hypertrophy. Methods Human and mouse hypertrophic heart tissues were used to determine the expression of KLK11 with quantitative real-time PCR and western blot. Mouse cardiac hypertrophy was induced by transverse aortic constriction (TAC), and cardiomyocyte hypertrophy was induced by angiotensin II. Cardiac function was analyzed by echocardiography. The signaling pathway was analyzed by western blot. Protein synthesis was monitored by the incorporation of [3H]-leucine. Gene expression was analyzed by quantitative real-time PCR. Results The mRNA and protein levels of KLK11 were upregulated in human hypertrophic hearts. We also induced cardiac hypertrophy in mice and observed the upregulation of KLK11 in hypertrophic hearts. Our in vitro experiments demonstrated that KLK11 overexpression promoted whereas KLK11 knockdown repressed cardiomyocytes hypertrophy induced by angiotensin II, as evidenced by cardiomyocyte size and the expression of hypertrophy-related fetal genes. Besides, we knocked down KLK11 expression in mouse hearts with adeno-associated virus 9. Knockdown of KLK11 in mouse hearts inhibited TAC-induced decline in fraction shortening and ejection fraction, reduced the increase in heart weight, cardiomyocyte size, and expression of hypertrophic fetal genes. We also observed that KLK11 promoted protein synthesis, the key feature of cardiomyocyte hypertrophy, by regulating the pivotal machines S6K1 and 4EBP1. Mechanism study demonstrated that KLK11 promoted the activation of AKT-mTOR signaling to promote S6K1 and 4EBP1 pathway and protein synthesis. Repression of mTOR with rapamycin blocked the effects of KLK11 on S6K1 and 4EBP1 as well as protein synthesis. Besides, rapamycin treatment blocked the roles of KLK11 in the regulation of cardiomyocyte hypertrophy. Conclusions Our findings demonstrated that KLK11 promoted cardiomyocyte hypertrophy by activating AKT-mTOR signaling to promote protein synthesis.

scholarly journals Biochemical characterization including amino acid and carbohydrate compositions of canine and human brain Thy-1 antigen

1981 ◽  
Vol 197 (3) ◽  
pp. 629-636 ◽  
Author(s):  
J L McKenzie ◽  
A K Allen ◽  
J W Fabre
Keyword(s):  
Monoclonal Antibody ◽  
Amino Acid ◽  
Human Brain ◽  
Affinity Chromatography ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Antibody Affinity ◽  
Lentil Lectin

Human and canine brain Thy-1 antigens were solubilized in deoxycholate and antigen activity was followed both by conventional absorbed anti-brain xenosera of proven specificity and by mouse monoclonal antibodies to canine and human Thy-1. It is shown that greater than 80% of Thy-1 activity in the dog and man binds to lentil lectin, that the mobility on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of canine and human Thy-1 is identical with that of rat Thy-1 and that the Stokes radius in deoxycholate of canine and human brain Thy-1 is 3.0 nm and 3.25 nm respectively. Both lentil lectin affinity chromatography followed by gel-filtration chromatography on the one hand and monoclonal antibody affinity chromatography on the other gave high degrees of purification of the brain Thy-1 molecule in the dog and man, resulting in single bands staining for both protein and carbohydrate on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis (except for a slight contaminant of higher molecular weight staining for protein but not carbohydrate with human Thy-1 purified by lentil lectin and gel-filtration chromatography). Analysis of canine and human brain Thy-1 purified by monoclonal antibody affinity chromatography with additional gel filtration through Sephadex G-200 showed that these molecules had respectively 38% and 36% carbohydrate. The amino acid and carbohydrate compositions were similar to those previously reported for Thy-1 of the rat and mouse, the main point of interest being the presence in canine and human brain Thy-1 of N-acetylgalactosamine, which has been reported in rat and mouse brain Thy-1 but not in Thy-1 from other tissues.

scholarly journals Studies on human pregnancy-associated plasma protein A. Purification by affinity chromatography and structural comparisons with α2-macroglobulin

1980 ◽  
Vol 191 (3) ◽  
pp. 799-809 ◽  
Author(s):  
R G Sutcliffe ◽  
B M Kukulska-Langlands ◽  
J R Coggins ◽  
J B Hunter ◽  
C H Gore
Keyword(s):  
Molecular Weight ◽  
Affinity Chromatography ◽  
Plasma Protein ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein A ◽  
Carbohydrate Content ◽  
Polyacrylamide Gel ◽  
Gel Chromatography ◽  
Tryptic Fragment

Pregnancy-associated plasma protein-A (PAPP-A) has been purified by a combination of methods including antibody-affinity chromatography. The resultant protein, obtained in 16% yield from maternal serum, appeared as a single major component on non-denaturing polyacrylamide and SDS/polyacrylamide gel electrophoresis. The protein showed a single component when analysed by isoelectric focusing under denaturing conditions in the presence and absence of reduction and had a pI of 4.34 and 4.42 respectively. These pI values were indistinguishable from those of alpha 2-macroglobulin (alpha 2M). The molecular weight of the PAPP-A polypeptide as shown by SDS/polyacrylamide-gel electrophoresis was 187000, with a minor component of mol.wt. 82500 that was attributed to proteolysis. Since native PAPP-A had a molecular weight on gel chromatography very similar to that of alpha 2M (620000–820000), it was concluded that PAPP-A was a homotetramer. In the absence of reduction, a high-molecular-weight (420000) protomer of PAPP-A was found. It was deduced that PAPP-A, like alpha 2M, is a dinner, whose protomers are composed of disulphide-linked polypeptide chains. It was found that the molecular weight of the PAPP-A polypeptide exceeded that of alpha 2M by 3.3%, but that the total carbohydrate content of PAPP-A exceeded that of alpha 2M by 10% and that its neutral carbohydrate content exceeded that of alpha 2M by between 7.4 and 9.0%. The significance of the estimated molecular weights of alpha 2M (181000) and its major tryptic fragments is discussed in the light of published values. A tryptic fragment alpha 2M (82500 mol.wt.) was apparently the same size as the major tryptic fragment of PAPP-A.

Affinity chromatography purification and partial characterization of phytohemagglutinin-receptor glycoproteins from porcine splenic lymphocytes

1985 ◽  
Vol 63 (9) ◽  
pp. 932-940 ◽  
Author(s):  
Gilles Dupuis ◽  
Jean-Pierre Doucet ◽  
Bânû Bastin ◽  
Jeannine Cardin
Keyword(s):  
Affinity Chromatography ◽  
Competitive Inhibition ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Interleukin 2 ◽  
Lymphocyte Activation ◽  
Scatchard Analysis ◽  
Dependent Manner ◽  
Murine Cell Line ◽  
Lymphocyte Cultures

We describe the isolation of pig spleen lymphocyte glycoproteins that interact with phytohemagglutinin (PHA), the lectin from Phaseolus vulgaris. Purification was achieved by affinity chromatography of a Nonidet P-40 extract of the cells on a PHA – Affi-Gel 10 column. The retained glycoproteins were eluted with an acidic (pH 3.0) glycine buffer and represented 1.9–2.4% of the amount of protein applied to the column. They contained 20 ± 1.3% hexose and 1.7 ± 0.7% fatty acids, on a weight basis. Electrophoretic analyses (sodium dodecyl sulfate – polyacrylamide gel electrophoresis) showed the presence of major Coomassie blue positive bands with apparent molecular masses of 50–55, 75, 95, 130, and 155 kdaltons along with minor bands of 20–40, 42, 45, 60–65, 175, and 200–250 kdaltons. The purified PHA-receptor glycoproteins inhibited, in a dose-dependent manner, the incorporation of [3H]thymidine in pig lymphocytes cultured at a concentration of 106 cells/mL in the presence of PHA. A 50% inhibition was observed when 20 μg/mL of the glycoproteins was added to the lymphocyte cultures containing 0.5 μg/mL of PHA. Scatchard analysis of the binding of 125I-labelled PHA, in the presence of increasing amounts of the purified glycoproteins, showed a suppression of the binding of the lectin to high affinity sites of the cells, as evidenced by a change from biphasic to a linear profile. Results of binding suggested a competitive inhibition by a population of purified glycoproteins with a similar affinity for the lectin. The purified glycoproteins decreased PHA-dependent interleukin 2 (IL-2) production by pig lymphocytes as assayed with a IL-2 dependent murine cell line. It is suggested that the affinity-purified PHA-reactive glycoproteins are inhibitors of PHA-dependent cellular responses because they compete with PHA-receptor sites on the lymphocyte plasma membrane. A mouse antiserum raised against the purified glycoproteins inhibited PHA-induced lymphocyte activation, but did not stimulate lymphocytes when added alone to lymphocyte cultures or in combination with a antimouse antiserum.

scholarly journals Ecological mechanisms in cognitive science

2019 ◽  
Vol 29 (5) ◽  
pp. 676-696 ◽  
Author(s):  
Sabrina Golonka ◽  
Andrew D. Wilson
Keyword(s):  
Simple Model ◽  
Circadian Rhythms ◽  
Cognitive Science ◽  
Real Time ◽  
Mechanistic Model ◽  
Mechanistic Explanation ◽  
Perceptual Information ◽  
Proof Of Concept ◽  
Time Interaction ◽  
Ecological Mechanisms

In 2010, Bechtel and Abrahamsen defined and described what it means to be a dynamic causal mechanistic explanatory model. They discussed the development of a mechanistic explanation of circadian rhythms as an exemplar of the process and challenged cognitive science to follow this example. This article takes on that challenge. A mechanistic model is one that accurately represents the real parts and operations of the mechanism being studied. These real components must be identified by an empirical programme that decomposes the system at the correct scale and localises the components in space and time. Psychological behaviour emerges from the nature of our real-time interaction with our environments—here we show that the correct scale to guide decomposition is picked out by the ecological perceptual information that enables that interaction. As proof of concept, we show that a simple model of coordinated rhythmic movement, grounded in information, is a genuine dynamical mechanistic explanation of many key coordination phenomena.

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