Calcium-binding proteins in a vorticellid contractile organelle

1975 ◽  
Vol 19 (1) ◽  
pp. 203-213
Author(s):  
W.B. Amos ◽  
L.M. Routledge ◽  
F.F. Yew
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Calcium Binding ◽  
Binding Proteins ◽  
Sodium Dodecyl ◽  
Aromatic Amino Acids ◽  
Calcium Binding Proteins ◽  
Polyacrylamide Gels ◽  
Protein Species ◽  
Low Concentrations

The proteins of the contractile spasmoneme of Zoothamnium have been examined for comparison with other motile systems. Though capable of calcium-induced contraction, glycerinated preparations of the spasmoneme contain neither actin nor tubulin at levels that can be detected in polyacrylamide gels. Sixty per cent of the protein in sodium dodecyl sulphate gels migrates in a band at a molecular weight of approximately 20,000, consisting largely of 2 similar protein species which are here given the name of spasmins. The amino acid composition of 2 spasmin fractions has been determined by a fluorimetric method. They are rich in Asx, Glx and serine, but have few aromatic amino acids and no cystine or methionine. In calcium-buffered polyacrylamide gels, it was observed that a reduction in the electrophoretic mobility of the spasmins was induced specifically by calcium (but not magnesium) at the same low concentrations as induce contraction. This indicates that the spasmins are calcium-binding proteins which may be involved directly in the calcium-induced contraction of the spasmoneme.

scholarly journals Calcium-binding proteins in the vorticellid spasmoneme

1978 ◽  
Vol 77 (2) ◽  
pp. 358-370 ◽  
Author(s):  
LM Routledge
Keyword(s):  
Molecular Weight ◽  
Calcium Binding ◽  
Binding Proteins ◽  
Striated Muscle ◽  
Guanidine Hydrochloride ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Dry Mass ◽  
Calcium Binding Proteins ◽  
Polyacrylamide Gel

The proteins of the contractile spasmoneme from Vorticella convallaria, Carcheslium polypinum, and Zoothamnium geniculatum have been extracted in the detergent, sodium dodecyl sulfate (SDS), as well as urea and guanidine hydrochloride (GuCl). After SDS extraction, the molecular weight distribution of the proteins was examined by means of SDS-polyacrylamide gel electrophoresis. Significant amounts of material corresponding to the contractile proteins actin and tubulin are not present. The contractile organelles in the three species examined contain a group of closely related proteins of molecular weight near 20,000, which constitute a major part (40-60%) of the dry mass. The 20,000 mol wt proteins in Zoothamnium bind calcium with high affinity (pK congruent to 6) and are termed "spasmins." By means of urea polyacrylamide gel electrophorsis, it is demonstrated that in Carchesium and Zoothamnium certain spasmin components bind calcium even in the presence of 6 M urea. The binding of calcium in 6 M urea suggests a functional relationship between the spasmins and the calcium-binding proteins of striated muscle which behave similarly. The calcium binding in urea also indicates that the spasmins within a single spasmoneme have different calcium affinities, and this difference in calcium-binding properties may be an important factor in the physiological function of the organelle.

scholarly journals Lectin-binding proteins in central-nervous-system myelin. Detection of glycoproteins of purified myelin on polyacrylamide gels by [3h]concanavalin A binding

1979 ◽  
Vol 183 (2) ◽  
pp. 205-212 ◽  
Author(s):  
L J McIntyre ◽  
R H Quarles ◽  
R O Brady
Keyword(s):  
Molecular Weight ◽  
Rat Brain ◽  
Concanavalin A ◽  
Binding Proteins ◽  
Lectin Binding ◽  
Sodium Dodecyl ◽  
Myelin Proteins ◽  
Polyacrylamide Gels ◽  
Myelin Associated Glycoprotein

Concanavalin A strongly agglutinates purified fragments of immature and mature rat brain myelin, but only weakly agglutinates mature bovine and human myelin fragments. A sensitive method involving [3H]concanavalin binding to sodium dodecyl sulphate/polyacrylamide gels was used to detect the concanavalin A-binding proteins in purified myelin. When applied to mature rat brain myelin proteins that had been labelled in vivo with [14C]fucose, the distribution of the [3H]concanavalin A on the gel was very similar to that of [14C]fucose with the major peak corresponding to the major myelin-associated glycoprotein. The technique revealed that the immature form of the myelin-associated glycoprotein with a slightly larger apparent molecular weight also bound concanavalin A, and that in purified immature rat myelin the quantitative importance of some of the other glycoproteins in binding concanavalin A was increased relative to the myelin-associated glycoprotein. The separated proteins of bovine and human myelin bound more [3H]-concanavalin A than those of rat myelin. In these species, the myelin-associated glycoprotein was a major concanavalin A-binding protein, although two higher-molecular-weight glycoproteins also bound significant quantities of [3H]concanavalin A. The results indicate that there are receptors for concanavalin A on the surface of rat, bovine and human myelin membranes and suggest that the myelin-associated glycoprotein is one of the principal receptors.

scholarly journals Calcium-ion-binding activity in human small-intestinal mucosal cytosol Purification of two proteins and interrelationship of calcium-binding fractions

1981 ◽  
Vol 197 (1) ◽  
pp. 55-65 ◽  
Author(s):  
M Davie
Keyword(s):  
Molecular Weight ◽  
Calcium Binding ◽  
Binding Proteins ◽  
Binding Protein ◽  
Mammalian Species ◽  
Binding Activity ◽  
Calcium Binding Proteins ◽  
Calcium Binding Protein ◽  
Small Intestinal Mucosa ◽  
Small Intestinal

Ca2+-binding activity was investigated in human small-intestinal mucosal cytosol. Binding was detected in fractions with molecular weights of 28000 and about 900000, as determined by gel filtration. No binding was found at molecular weight 12000-13000 (the molecular weight of calcium-binding protein in lower mammalian species) until the cytosol had been subjected to a hollow-fibre-filtration step. The appearance of Ca2+-binding at molecular weight 12000-13000 was associated with a decline in the 28000-mol.wt. calcium-binding fraction. The 12000-13000-mol.wt. fraction contained two distinct calcium-binding proteins. One of these proteins had properties similar to those of pig calcium-binding protein. Antiserum to this protein reacted against the 28000-mol.wt calcium-binding fraction in cytosol from human small-intestinal mucosa and from human kidney. An immunoassay method for one of the calcium-binding proteins was established. In normal duodenal mucosa the concentration was 915 micrograms/g and in the ileum it was 443 micrograms/g of mucosa. A subject with hypercalcaemic sarcoidosis had 1200 micrograms/g of mucosa in the jejunum, and a subject with an undetectable concentration of plasma 25-hydroxycholecalciferol had concentrations of calcium-binding protein in the mucosa similar to those found in normal subjects.

Detection of Calcium Binding Proteins on Polyacrylamide Gels Using Time-Resolved Lanthanide Luminescence Photography

1994 ◽  
Vol 216 (2) ◽  
pp. 439-443 ◽  
Author(s):  
I.E. Hill ◽  
C.W.V. Hogue ◽  
I.D. Clark ◽  
J.P. Macmanus ◽  
A.G. Szabo
Keyword(s):  
Calcium Binding ◽  
Binding Proteins ◽  
Calcium Binding Proteins ◽  
Polyacrylamide Gels ◽  
Time Resolved ◽  
Lanthanide Luminescence

How Important are S100A8/S100A9 Calcium Binding Proteins for the Activation of Phagocyte NADPH Oxidase, Nox2

2009 ◽  
Vol 8 (4) ◽  
pp. 282-289 ◽  
Author(s):  
Sylvie Berthier ◽  
Athan Baillet ◽  
Marie-Helene Paclet ◽  
Philippe Gaudin ◽  
Francoise Morel
Keyword(s):  
Nadph Oxidase ◽  
Calcium Binding ◽  
Binding Proteins ◽  
Calcium Binding Proteins ◽  
Phagocyte Nadph Oxidase
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