scholarly journals Calmodulin confers calcium sensitivity on ciliary dynein ATPase.

1980 ◽  
Vol 87 (2) ◽  
pp. 386-397 ◽  
Author(s):  
J J Blum ◽  
A Hayes ◽  
G A Jamieson ◽  
T C Vanaman
Keyword(s):  
Molecular Weight ◽  
Atpase Activity ◽  
High Molecular Weight ◽  
Binding Sites ◽  
Calcium Sensitivity ◽  
Bovine Brain ◽  
Calmodulin Binding ◽  
Dependent Atpase ◽  
Low Concentrations ◽  
Sepharose 4B

Extraction of demembranated cilia of Tetrahymena by Tris-EDTA (denoted by the suffix E) yields 14S-E and 30S-E dyneins with ATPase activities that are slightly increased by Ca++. This effect is moderately potentiated when bovine brain calmodulin is added to the assay mixture. Extraction with 0.5 M KCl (denoted by the suffix K) yeilds a 14S-K dynein with a low basal ATPase activity in the presence of Ca++. Subsequent addition of calmodulin causes marked activation (up to 10-fold) of ATPase activity. Although 14S-K and 14S-E dyneins have Ca++-dependent ATPase activities that differ markedly in the degree of activation, the concentration of calmodulin required for half-maximal saturation is similar for both, approximately 0.1 microM. Both 30S-K and 30S-E dyneins, however, require approximately 0.7 microM bovine brain calmodulin to reach half-maximal activation of their Ca++-dependent ATPase activities. Tetrahymena calmodulin is as effective as bovine brain calmodulin in activating 30S dynein , but may be slightly less effective than the brain calmodulin in activating 14S dynein. Rabbit skeletal muscle troponin C also activates the Ca++-dependent ATPase activity of 30S dynein and, to a lesser extent, that of 14S dynein, but in both cases is less effective than calmodulin. The interaction of calmodulin with dynein that results in ATPase activation is largely complete in less than 1 min, and is prevented by the presence of low concentrations of ATP. Adenylyl imidodiphosphate can partially prevent activation of dynein ATPase by calmodulin plus Ca++, but at much higher concentrations than required for prevention by ATP. beta, gamma-methyl-adenosine triphosphate appears not to prevent this activation. The presence of Ca++-dependent calmodulin-binding sites on 14S and 30S dyneins was demonstrated by the Ca++-dependent retention of the dyneins on a calmodulin-Sepharose-4B column. Gel electrophoresis of 14S dynein that had been purified by the affinity-chromatography procedure showed that presence of two major and one minor high molecular weight components. Similar analysis of 30S dynein purified by this procedure also revealed on major and one minor high molecular weight components that were different from the major components of 14S dynein. Ca++-dependent binding sites for calmodulin were shown to be present on axonemes that had been extracted twice with Tris-EDTA or with 0.5 M KCl by the use of 35S-labeled Tetrahymena calmodulin. It is concluded that the 14S and 30S dyneins of Tetrahymena contain Ca++-dependent binding sites for calmodulin and the calmodulin mediates the Ca++-regulation of the dynein ATPases of Tetrahymena cilia.

scholarly journals Identity and Origin of the ATPase activity associated with neuronal microtubules. I. The ATPase activity is associated with membrane vesicles.

1983 ◽  
Vol 96 (5) ◽  
pp. 1298-1305 ◽  
Author(s):  
D B Murphy ◽  
R R Hiebsch ◽  
K T Wallis
Keyword(s):  
Molecular Weight ◽  
Atpase Activity ◽  
High Molecular Weight ◽  
Brain Tissue ◽  
Membrane Vesicles ◽  
Microtubule Associated Proteins ◽  
In Vitro Assembly ◽  
Microtubule Protein ◽  
Associated Proteins

Microtubule protein purified from brain tissue by cycles of in vitro assembly-disassembly contains ATPase activity that has been postulated to be associated with microtubule-associated proteins (MAPs) and therefore significant for studies of microtubule-dependent motility. In this paper we demonstrate that greater than 90% of the ATPase activity is particulate in nature and may be derived from contaminating membrane vesicles. We also show that the MAPs (MAP-1, MAP-2, and tau factors) and other high molecular weight polypeptides do not contain significant amounts of ATPase activity. These findings do not support the concept of "brain dynein" or of MAPs with ATPase activity.

High molecular weight polypeptides related to dynein heavy chains in Nicotiana tabacum pollen tubes

1995 ◽  
Vol 108 (3) ◽  
pp. 1117-1125
Author(s):  
A. Moscatelli ◽  
C. Del Casino ◽  
L. Lozzi ◽  
G. Cai ◽  
M. Scali ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nicotiana Tabacum ◽  
Pollen Tube ◽  
High Molecular Weight ◽  
Pollen Tubes ◽  
Biochemical Properties ◽  
Bovine Brain ◽  
Atp Binding ◽  
Heavy Chains ◽  
Dynein Heavy Chains

Nicotiana tabacum pollen tubes contain two high molecular weight polypeptides (about 400 kDa), which are specifically expressed during pollen germination and pollen tube growth in BK medium. The high molecular weight doublet resembles the dynein heavy chains in some biochemical properties. Sedimentation profiles of pollen tube extracts show that the high molecular weight bands have sedimentation coefficients of 22 S and 12 S, respectively. ATPase assay of sedimentation fractions shows an activity ten times higher when stimulated by the presence of bovine brain microtubules in fractions containing the 22 S high molecular weight polypeptide. Both these high molecular weight polypeptides can bind microtubules in an ATP-dependent fashion. A mouse antiserum to a synthetic peptide reproducing the sequence of the most conserved ATP-binding site among dynein heavy chains recognized the two high molecular weight polypeptides. Therefore these polypeptides have sequences immunologically related to the ATP binding sites of dynein heavy chains.

Effect of Azide on the ATPase Activity of Isolated CF1

1991 ◽  
Vol 46 (7-8) ◽  
pp. 621-628 ◽  
Author(s):  
Ignat B. Minkov ◽  
Heinrich Strotmann
Keyword(s):  
Atpase Activity ◽  
Enzyme Activation ◽  
Applied Method ◽  
Spinach Chloroplasts ◽  
Dependent Atpase ◽  
Low Concentrations ◽  
Activation Heat

Abstract The effect of azide on M g2+-and Ca2+-dependent ATPase of differently activated CF1 isolated from spinach chloroplasts was studied. It is shown that Mg2+-ATPase activity is sensitive towards azide irrespective of the applied method of enzyme activation. Heat-or trypsin-acti-vated Ca2+-ATPase is also inhibited, whereas methanol-and octylglucoside-stimulated or DTT-activated Ca2+-ATPase is not affected by azide. Preincubation of the DTT-activated enzyme with low concentrations of Mg2+ induces azide susceptibility of the Ca2+-dependent ATPase.

Three noncontiguous peptides comprise binding sites on high-molecular-weight kininogen to neutrophils

1998 ◽  
Vol 275 (1) ◽  
pp. H145-H150 ◽  
Author(s):  
Mohammad M. H. Khan ◽  
Satya P. Kunapuli ◽  
Yingzhang Lin ◽  
Abraham Majluf-Cruz ◽  
Raul A. Dela Cadena ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Binding Site ◽  
High Molecular Weight ◽  
Binding Sites ◽  
Polymorphonuclear Leukocytes ◽  
High Molecular Weight Kininogen ◽  
Rich Region ◽  
Putative Receptor ◽  
Exon 9 ◽  
Stimulation Of

The binding of high-molecular-weight kininogen (HK) to neutrophils (polymorphonuclear leukocytes, PMN) is required for the stimulation of aggregation and degranulation by human plasma kallikrein as well as the displacement of fibrinogen from this cell surface. The putative receptor for HK is the leukocyte integrin αMβ2, and domains 3 (D3) and 5 (D5) of HK form its binding site. To further map the binding sites on HK for PMN, we used D3 recombinant exon products and designed peptides from D3 and D5. In D3, a heptapeptide, Leu271-Ala277, from exon 7 product, and a peptide, Cys333-Cys352, from exon 9 product can inhibit binding of kininogen to PMN. Two contiguous peptides from D5 in the histidine-glycine-rich region, Gly442-Lys458and Phe459-Lys478, each inhibit the binding of HK to PMN. This study has thus delineated three noncontiguous surface-oriented sequences on HK, which together comprise all or most of the binding site for human PMN.

The high-molecular-weight proteins of bovine brain plain synaptic vesicles

1987 ◽  
Vol 12 (7) ◽  
pp. 635-640
Author(s):  
Paul E. March ◽  
Edna Antonian ◽  
Diane M. Schneider ◽  
David M. Rothwarf ◽  
Edward R. Thornton
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Synaptic Vesicles ◽  
Bovine Brain ◽  
High Molecular Weight Proteins

CULTURED HUMAN ENDOTHELIAL CELLS BIND AND INTERNALIZE HIGH MOLECULAR WEIGHT KININOGEN

1987 ◽  
Author(s):  
Freek van Iwaarden ◽  
G Philip ◽  
de Groot ◽  
Bonno N Bouma
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Surface ◽  
High Molecular Weight ◽  
Binding Sites ◽  
High Molecular Weight Kininogen ◽  
Human Endothelial Cells ◽  
Endothelial Cell Surface ◽  
Coagulation Pathway

The presence of High Molecular Weight kininogen (HMWK) was demonstrated in cultured human endothelial cells (EC) by immunofluorescence techniques. Using an enzyme linked immunosorbent assay a concentration of 58 ng HMWK/10 cells was determined. Immunoprecipitation studies performed with lysed metabolically labelled endothelial cells and mono-specific antisera directed against HMWK suggested that HMWK is not synthesized by the endothelial cells. Endothelial cells cultured in the presence of HMWK-depleted serum did not contain HMWK. This, suggests that endothelial cells can internalize HMWK. Using 125I-HMWK it was demonstrated that cultured endothelial cells bind HMWK in a time-dependent, specific and saturable.way. The cells were found to internalize 125I-HMWK, since I-HMWK was detected in solubilized endothelial cells after the cell bound 125I-HMWK had been eluted with dextran sulphate.The binding of I-HMWK required the presence of zinc ions. Optimal binding of 125I-HMWK was observed at 50 μM Zn++ . Calcium ions inhibited the Zn++ dependent binding of 125I-HMWK |25EC. In the presence of 3 mM CaCl2 the total binding of 125I-HMWK was significantly decreased, and a .concentration of 200 μM Zn++ was Required for the binding of 125I-HMWK to thecells. Higher,. Ca concentrations did not further decrease the binding of 125I-HMWK. Analysis of tl^e binding data by the ligand computer program indicated 3.2 x 10 binding sites per cell for HMWK with a Kd of 35 nM at 50 μM ZnCl2 and 1 mM CaCl2. Specify binding of HMWK did also occur at physiological plasma Zn++ concentrations. Half maximal binding was observed at HMWK concentrations of ± 105 nM at 10 μM ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 10 molecules of HMWK bound per cell and at 80 nM with 2.8 x 10 molecules of HMWK bound per cell at 10 and 25 pM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway. M ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 10 molecules of HMWK bound per cell and at 80 nM with 2.8 x 10 molecules of HMWK bound per cell at 10 and 25 μM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway. M ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 10 molecules of HMWK bound per cell and at 80 nM with 2.8 x 10 molecules of HMWK bound per cell at 10 and 25 μM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway. M ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 10 molecules of HMWK bound per cell and at 80 nM with 2.8 x 10 molecules of HMWK bound per cell at 10 and 25 μM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway.M ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 16 molecules of HMWK bound per cell and at 80 nM with 2.8 x 106 molecules of HMWK bound per cell at 10 and 25 μM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway.

Cardiac High Molecular Weight Calmodulin Binding Protein Contains Calpastatin Activity†

Biochemistry ◽  
1997 ◽  
Vol 36 (39) ◽  
pp. 11550-11555 ◽  
Author(s):  
Rakesh Kakkar ◽  
Rajala V. S. Raju ◽  
Ronald L. Mellgren ◽  
Jasim Radhi ◽  
Rajendra K. Sharma
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Binding Protein ◽  
Calmodulin Binding

Regulation of high molecular weight bovine brain neutral protease by phospholipids in vitro

2005 ◽  
Vol 272 (1-2) ◽  
pp. 145-149 ◽  
Author(s):  
V. Chauhan ◽  
A. M. Sheikh ◽  
A. Chauhan ◽  
W. D. Spivack ◽  
M. D. Fenko ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Bovine Brain ◽  
Neutral Protease

scholarly journals Iodination of Calsequestrin in the Sarcoplasmic Reticulum of Rabbit Skeletal Muscle: A Re-Examination

1979 ◽  
Vol 32 (2) ◽  
pp. 177 ◽  
Author(s):  
Ronald K Tume
Keyword(s):  
Skeletal Muscle ◽  
Molecular Weight ◽  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Calcium Binding ◽  
Local Environment ◽  
Maximal Inhibition ◽  
High Affinity ◽  
Tris Maleate ◽  
Sepharose 4B

The exposed proteins of sarcoplasmic reticulum (SR) vesicles from skeletal muscle were iodinated with the use of Sepharose 4B-bound lactoperoxidase, so that the location of the proteins in the membrane could be determined. It was found that the pattern of protein labelling could be modified simply by changing the constituents of the incubation media. This implies that the position or configuration of a particular protein in the membrane can be altered by the local environment. When the reaction was performed in the presence of 25 mM tris-maleate, pH 7 �0, alone, the Ca2+ pump ATPase (molecular weight 105000) and calsequestrin (47000) were both heavily labelled, suggesting they are at least partially exposed on the outer surface of the membrane. By contrast the high affinity calcium-binding protein (55000) was not labelled. However, when the vesicles were iodinated under conditions that were suitable for ATPase activity and Ca2+ accumulation, namely in the presence of 25 mM tris-maleate, pH 7 �0, 5 mM ATP, 5 mM Mg2+ and 0�05 mM Ca2+, a different pattern of labelling was obtained. No labelling of calsequestrin was observed whereas the extent of labelling of the Ca2+ pump ATPase remained about the same. The inclusion of anyone of the additives mentioned was effective in inhibiting the iodination of calsequestrin in the SR vesicle. When added alone, Ca2+ was more effective than Mg2+ in preventing labelling of calsequestrin. Half-maximal inhibition was observed at concentrations of approximately 0�05 mM Ca 2+ and 0�2-0�3 mM Mg2+ . Although much reduced, significant labelling of calsequestrin was observed even in the presence of 5 mM ATP. Investigations with partially purified calsequestrin revealed that the iodination of calsequestrin was the same in both the presence and absence of 1 mM Ca2 +. Therefore the reduction in label observed in intact SR vesicles probably represents a change in the location of calsequestrin within the membrane, rather than inhibition by Ca2+ of the iodination sites of the protein itself.

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