An Antibody to Annexin V Blocks Ca2+-Dependent ATPase Activity of Sarcoplasmic Reticulum in Human Failing Hearts

1998 ◽  
Vol 853 (1 CARDIAC SARCO) ◽  
pp. 333-337 ◽  
Author(s):  
ION I. MORARU ◽  
SERGEI SYRBU ◽  
NADA ZECEVIC ◽  
DAVID W. HAGER ◽  
JAMES WATRAS ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Annexin V ◽  
Dependent Atpase

Transient Activation of the Ca2+-ATPase from Sarcoplasmic Reticulum during Thiol Modification by 5 ,5′-Dithiobis(2-nitrobenzoate)

1983 ◽  
Vol 38 (9-10) ◽  
pp. 834-844 ◽  
Author(s):  
Gertrude Swoboda ◽  
Wilhelm Hasselbach
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Control Level ◽  
State Level ◽  
Control Activity ◽  
Activity Maximum ◽  
Dependent Atpase ◽  
Transient Activation ◽  
Initial Stage ◽  
Modification Rate

In the reaction of sarcoplasmic reticulum m em branes with excess 5,5′-dithiobis(2-nitrobenzoate) (DTNB) some new features were observed:1) The Ca2+-dependent ATPase activities of increasingly modified preparations were considerably enhanced during the initial stage of thiol blockage. A maximum (130 -160% of the control activity) was reached when about 1.5 - 2 mol thiol groups per 105 g vesicular protein had reacted, in the absence of ATP and detergent. At higher extents of modification inactivation occurred. Purified ATPase behaved principally similar to native sarcoplasmic vesicles. 2) In the presence of Mg2+ and ATP the activity maxim um (up to 180% of control) was broadened and shifted towards a higher degree of thiol blockage. Concomitantly the modification and inactivation rates were considerably reduced. 3) Glycerol (10 -30 % , v/v) slightly enhanced the ATPase activity maximum and reduced the rate of inactivation essentially only by decreasing the DTNB modification rate. 4) In the presence of sufficient myristoylglycerophosphocholine for solubilization no activation was observed. 5) The steady state level of phosphoprotein from ATP was raised to about 150% of the control level 10 s after addition of DTNB (about 1/2 thiol blocked), followed by a linear decrease with the number of thiols labeled, while the Ca2+-dependent ATPase activity of preparations modified under equivalent conditions (10-4 м Ca2+ and 2 x 10-3 м Mg2+ present) showed a broader maximum corresponding to 1.5 thiols blocked.

scholarly journals Biochemical heterogeneity of skeletal-muscle microsomal membranes. Membrane origin, membrane specificity and fibre types

1982 ◽  
Vol 202 (2) ◽  
pp. 289-301 ◽  
Author(s):  
Giovanni Salviati ◽  
Pompeo Volpe ◽  
Sergio Salvatori ◽  
Romeo Betto ◽  
Ernesto Damiani ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Total Phospholipid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Freeze Fracture ◽  
Sucrose Density Gradient ◽  
Average Density ◽  
Slow Muscle ◽  
Fast And Slow Muscle ◽  
Dependent Atpase

1. Microsomes were isolated from rabbit fast-twitch and slow-twitch muscle and were separated into heavy and light fractions by centrifugation in a linear (0.3–2m) sucrose density gradient. The membrane origin of microsomal vesicles was investigated by studying biochemical markers of the sarcoplasmic-reticulum membranes and of surface and T-tubular membranes, as well as their freeze-fracture properties. 2. Polyacrylamide-gel electrophoresis showed differences in the Ca2+-dependent ATPase/calsequestrin ratio between heavy and light fractions, which were apparently consistent with their respective origin from cisternal and longitudinal sarcoplasmic reticulum, as well as unrelated differences, such as peptides specific to slow-muscle microsomes (mol.wts. 76000, 60000, 56000 and 45000). 3. Freeze-fracture electron microscopy of muscle microsomes demonstrated that vesicles truly derived from the sarcoplasmic reticulum, with an average density of 9nm particles on the concave face of about 3000/μm2 for both fast and slow muscle, were admixed with vesicles with particle densities below 1000/μm2. 4. As determined in the light fractions, the sarcoplasmic-reticulum vesicles accounted for 84% and 57% of the total number of microsomal vesicles, for fast and slow muscle respectively. These values agreed closely with the percentage values of Ca2+-dependent ATPase protein obtained by gel densitometry. 5. The T-tubular origin of vesicles with a smooth concave fracture face in slow-muscle microsomes is supported by their relative high content in total phospholipid and cholesterol, compared with the microsomes of fast muscle, and by other correlative data, such as the presence of (Na++K+)-dependent ATPase activity and of low amounts of Na+-dependent membrane phosphorylation. 6. Among intrinsic sarcoplasmic-reticulum membrane proteins, a proteolipid of mol.wt. 12000 is shown to be identical in the microsomes of both fast and slow muscle and the Ca2+-dependent ATPase to be antigenically and catalytically different, though electrophoretically homogeneous. 7. Basal Mg2+-activated ATPase activity was found to be high in light microsomes from slow muscle, but its identification with an enzyme different from the Ca2+-dependent ATPase is still not conclusive. 8. Enzyme proteins that are suggested to be specific to slow-muscle longitudinal sarcoplasmic reticulum are the flavoprotėin NADH:cytochrome b5 reductase (mol.wt. 32000), cytochrome b5 (mol.wt. 17000) and the stearoyl-CoA desaturase, though essentially by criteria of plausibility.

Regulation of sarcoplasmic reticulum calcium pump gene expression by hindlimb unweighting

1993 ◽  
Vol 264 (5) ◽  
pp. C1308-C1315 ◽  
Author(s):  
L. M. Schulte ◽  
J. Navarro ◽  
S. C. Kandarian
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Blot Analysis ◽  
Time Course ◽  
Contractile Properties ◽  
Mrna Levels ◽  
Relative Expression ◽  
Hindlimb Unweighting ◽  
Time Points ◽  
Dependent Atpase

Hindlimb unweighting (HU) causes upregulation of several muscle-specific genes responsible for the slow-to-fast transition in soleus skeletal muscle properties despite the profound muscle atrophy. The purpose of this study was to examine the expression of the fast and slow isoforms of the sarcoplasmic reticulum Ca(2+)-ATPase at the mRNA and protein level in the soleus muscle over a time course of HU and relate them to Ca(2+)-dependent ATPase activity and selected contractile properties. mRNA levels of the acetylcholine receptor (AChR) were measured to compare the signal of unweighting with denervation. Atrophy of the soleus muscles from tail-suspended rats was observed at all time points with muscle mass decreased by 52% at 28 days of HU (P < 0.05). Northern blot analysis showed the relative expression of the fast Ca2+ pump mRNA increased by 0, 250, 910, 1,340, and 4,050% over control levels at 1, 4, 7, 14, and 28 days of HU, respectively, whereas changes in slow mRNA were variable and modest in comparison. For the same time points, Western blot analysis showed relative expression of the fast Ca2+ pump protein increased by 30, 110, 320, 280, and 300% over control levels, whereas the slow-pump protein expression was unchanged except for a 75% decrease at 28 days of HU. Specific Ca(2+)-dependent ATPase activity was increased (P < 0.05) by 170% at 28 days of HU. Contractile properties measured in vitro at 14 and 28 days revealed time to peak tension and one-half relaxation time were shortened (P < 0.05) and a rightward shift in the tension-frequency curves in unloaded soleus muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Alteration of sarcoplasmic reticulum after denervation of chicken pectoralis muscle

1983 ◽  
Vol 210 (2) ◽  
pp. 339-344 ◽  
Author(s):  
C A Tate ◽  
R J Bick ◽  
T D Myers ◽  
B J R Pitts ◽  
W B Van Winkle ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Protein Profile ◽  
Pectoralis Muscle ◽  
Denervated Muscle ◽  
Single Class ◽  
Adult Chicken ◽  
Control Value ◽  
Dependent Atpase ◽  
Fast Twitch

To determine the neural influence on the function of the sarcoplasmic reticulum (SR) of fast-twitch skeletal muscle, the superior pectoralis muscle of adult chicken was denervated, and the SR was isolated at 20 days post-denervation. The isolated SR was probably derived from the longitudinal SR and was relatively free of contaminants. The protein profile of the SR was quantitatively changed after denervation with an increase in the M55 and 30000-mol.wt. proteins relative to the Ca2+-ATPase. Ca2+-dependent ATPase activity and phosphoenzyme formation were lower in the denervated-muscle SR; however, the enzyme catalytic-centre activity was similar to the control value. The decrease in Ca2+-ATPase activity in denervated-muscle SR was accompanied by a lower Ca2+ accumulation so that the relationship between Ca2+ accumulation and Ca2+-dependent ATPase activity was well maintained in the SR from denervated muscle. The data imply that denervation may result in a diminution of functional Ca2+ pump sites. Evidence is presented, though, which suggests that denervation affects a single class of Ca2+-binding sites of the Ca2+-ATPase, resulting in a lower affinity for Ca2+.

scholarly journals The effect of dantrolene on skeletal-muscle sarcoplasmic-reticulum function in malignant hyperpyrexia in pigs

1983 ◽  
Vol 212 (2) ◽  
pp. 399-405 ◽  
Author(s):  
M D White ◽  
J G Collins ◽  
M A Denborough
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Muscle Relaxant ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Malignant Hyperpyrexia ◽  
Dependent Atpase ◽  
Sarcoplasmic Reticulum Membrane

The effect of the muscle relaxant dantrolene on isolated sarcoplasmic reticulum was studied in control and malignant-hyperpyrexia-susceptible Landrace pigs. The membranes prepared from both sources showed similar Ca2+-dependent ATPase activities, had comparable phospholipid/protein ratios, and their sodium dodecyl sulphate/polyacrylamide-gel patterns were indistinguishable. Membranes from both sources appeared to bind similar amounts of dantrolene. The drug did not stimulate Ca2+-dependent ATPase activity in preparations from either source. The rates of Ca2+ exchange and Ca2+ efflux appeared to be similar in sarcoplasmic reticulum of control and malignant-hyperpyrexia-susceptible pigs. Dantrolene did not affect either the rates or the amount of Ca2+ lost from the vesicles. These results suggest that dantrolene does not directly affect the movement of Ca2+ across the sarcoplasmic-reticulum membrane.

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