Rapid Kinetic Studies of SH Oxidation-Induced Calcium Release from Sarcoplasmic Reticulum Vesicles

Donoso, P; Rodriguez, P.H.; Marambio, Paola

doi:10.1006/abbi.1997.9960

Cited by 11 publications

(3 citation statements)

References 18 publications

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“…Thus, triads actively loaded with calcium and extensively oxidized with thimerosal displayed even in 1 mM [Mg 2ϩ ] the same k values that were obtained in the absence of Mg 2ϩ . These findings agree with our previous report (Donoso et al, 1997) showing that oxidation of SR vesicles with 500 M 2,2Ј-dithiodipyridine does not increase the rate constants of ATP-induced calcium release measured without Mg 2ϩ at pCa 5.…”

Section: Sh Oxidation Modified the Inhibitory Effect Of Mg 2؉ On Cicrsupporting

confidence: 94%

Sulfhydryl Oxidation Overrides Mg2+ Inhibition of Calcium-Induced Calcium Release in Skeletal Muscle Triads

Donoso

Aracena-Parks

Hidalgo

2000

Biophysical Journal

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We studied the effect of oxidation of sulfhydryl (SH) residues on the inhibition by Mg(2+) of calcium-induced calcium release (CICR) in triad-enriched sarcoplasmic reticulum vesicles isolated from rabbit skeletal muscle. Vesicles were either passively or actively loaded with calcium before eliciting CICR by dilution at pCa 4.6-4.4 in the presence of 1.2 mM free [ATP] and variable free [Mg(2+)]. Native triads exhibited a significant inhibition of CICR by Mg(2+), with a K(0.5) approximately 50 microM. Partial oxidation of vesicles with thimerosal produced a significant increase of release rate constants and initial release rates at all [Mg(2+)] tested (up to 1 mM), and shifted the K(0.5) value for Mg(2+) inhibition to 101 or 137 microM in triads actively or passively loaded with calcium, respectively. Further oxidation of vesicles with thimerosal completely suppressed the inhibitory effect of [Mg(2+)] on CICR, yielding initial rates of CICR of 2 micromol/(mg x s) in the presence of 1 mM free [Mg(2+)]. These effects of oxidation on CICR were fully reversed by SH reducing agents. We propose that oxidation of calcium release channels, by decreasing markedly the affinity of the channel inhibitory site for Mg(2+), makes CICR possible in skeletal muscle.

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Section: Sh Oxidation Modified the Inhibitory Effect Of Mg 2؉ On Cicrsupporting

confidence: 94%

Sulfhydryl Oxidation Overrides Mg2+ Inhibition of Calcium-Induced Calcium Release in Skeletal Muscle Triads

Donoso

Aracena-Parks

Hidalgo

2000

Biophysical Journal

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“…Toxic O # species are involved in increased concentrations of cytosolic Ca# + because they oxidize critical residues in Ca channel proteins. In animal cells, Ca efflux from Caaccumulating organelles is enhanced when kSH residues in Ca channels are oxidized by toxic O # species (Stoyanovsky et al, 1994 ;Donoso et al, 1997). Similarly, in Zn-deficient plant cells an enhanced free radical-dependent oxidation of kSH groups and other critical residues of Ca channels might be expected.…”

Section: Alterations In Ion Absorptionmentioning

confidence: 99%

Tansley Review No. 111

2000

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Zinc deficiency is one of the most widespread micronutrient deficiencies in plants and causes severe reductions in crop production. There are a number of physiological impairments in Zn-deficient cells causing inhibition of the growth, differentiation and development of plants. Increasing evidence indicates that oxidative damage to critical cell compounds resulting from attack by reactive O # species (ROS) is the basis of disturbances in plant growth caused by Zn deficiency. Zinc interferes with membrane-bound NADPH oxidase producing ROS. In Zn-deficient plants the iron concentration increases, which potentiates the production of free radicals. The Zn nutritional status of plants influences photooxidative damage to chloroplasts, catalysed by ROS. Zinc-deficient leaves are highly light-sensitive, rapidly becoming chlorotic and necrotic when exposed to high light intensity. Zinc plays critical roles in the defence system of cells against ROS, and thus represents an excellent protective agent against the oxidation of several vital cell components such as membrane lipids and proteins, chlorophyll, SH-containing enzymes and DNA. The cysteine, histidine and glutamate or aspartate residues represent the most critical Znbinding sites in enzymes, DNA-binding proteins (Zn-finger proteins) and membrane proteins. In addition, animal studies have shown that Zn is involved in inhibition of apoptosis (programmed cell death) which is preceded by DNA and membrane damage through reactions with ROS.

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“…Thus SH reagents (Abramson et al, 1995), free radicals (Stoyanovsky et al, 1994), and hydrogen peroxide (Favero et al, 1995) activate RyR channels incorporated into planar lipid bilayers. Heavy metals (Abramson et al, 1983;Trimm et al, 1986;Salama et al, 1992), mercurials (Bindoli and Fleischer, 1983), dithiodipyridines (Nagura et al, 1988;Prabhu and Salama, 1990;Donoso et al, 1997), and derivatives of nitric oxide (Stoyanovsky et al, 1997) trigger calcium release from isolated SR vesicles as well. Furthermore, SH reagents shift the calcium activation curve of ryanodine binding to the left (Stuart et al, 1992;Favero et al, 1995), and heavy metals enhance the calcium sensitivity of tension development in skinned fibers from rabbit psoas muscle (Salama et al, 1992).…”

Section: Introductionmentioning

confidence: 99%

Sulfhydryl Oxidation Modifies the Calcium Dependence of Ryanodine-Sensitive Calcium Channels of Excitable Cells

Marengo

Hidalgo

Bull

1998

Biophysical Journal

197

155

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The calcium dependence of ryanodine-sensitive single calcium channels was studied after fusing with planar lipid bilayers sarcoendoplasmic reticulum vesicles isolated from excitable tissues. Native channels from mammalian or amphibian skeletal muscle displayed three different calcium dependencies, cardiac (C), mammalian skeletal (MS), and low fractional open times (low Po), as reported for channels from brain cortex. Native channels from cardiac muscle presented only the MS and C dependencies. Channels with the MS or low Po behaviors showed bell-shaped calcium dependencies, but the latter had fractional open times of <0.1 at all [Ca2+]. Channels with C calcium dependence were activated by [Ca2+] < 10 microM and were not inhibited by increasing cis [Ca2+] up to 0.5 mM. After oxidation with 2,2'-dithiodipyridine or thimerosal, channels with low Po or MS dependencies increased their activity. These channels modified their calcium dependencies sequentially, from low Po to MS and C, or from MS to C. Reduction with glutathione of channels with C dependence (native or oxidized) decreased their fractional open times in 0.5 mM cis [Ca2+], from near unity to 0.1-0.3. These results show that all native channels displayed at least two calcium dependencies regardless of their origin, and that these changed after treatment with redox reagents.

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Rapid Kinetic Studies of SH Oxidation-Induced Calcium Release from Sarcoplasmic Reticulum Vesicles

Cited by 11 publications

References 18 publications

Sulfhydryl Oxidation Overrides Mg2+ Inhibition of Calcium-Induced Calcium Release in Skeletal Muscle Triads

Sulfhydryl Oxidation Overrides Mg2+ Inhibition of Calcium-Induced Calcium Release in Skeletal Muscle Triads

Tansley Review No. 111

Sulfhydryl Oxidation Modifies the Calcium Dependence of Ryanodine-Sensitive Calcium Channels of Excitable Cells

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