What question did this study set out to answer?

To examine the proteolytic fragmentation, structural conformation, and ion-binding characteristics of rabbit skeletal muscle calsequestrin, focusing on its carboxyl-terminal domain.

November 1, 1987Biochemistry

Fragmentation of rabbit skeletal muscle calsequestrin: spectral and ion-binding properties of the carboxyl-terminal region

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Authors

MOMamoru OhnishiHiratsuka City Hospital RRReinhart A.F. ReithmeierUniversity of Toronto

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Implication

Biochemical analysis demonstrates calcium-binding and structural properties of calsequestrin in rabbit muscle, suggesting specialized ion storage roles.

Key Points

To examine the proteolytic fragmentation, structural conformation, and ion-binding characteristics of rabbit skeletal muscle calsequestrin, focusing on its carboxyl-terminal domain.
Digested rabbit skeletal muscle calsequestrin with trypsin in the presence and absence of calcium.
Sequenced an isolated 59-residue carboxyl-terminal tryptic peptide using automated Edman degradation and carboxypeptidase Y digestion.
Characterized peptide secondary structure and ion affinities using circular dichroism, intrinsic tryptophan fluorescence, and terbium-binding assays.
Calcium protected calsequestrin against tryptic proteolysis, yielding stable fragments that preserved calcium-binding activity despite diminished helical content.
The 59-residue carboxyl-terminal peptide was highly acidic (42% Asp + Glu, 0% Lys + Arg), binding 15 calcium ions per mole of peptide (Kd = 8.5 mM) and 7 moles of terbium per mole (Kd = 7.5 µM).
Circular dichroism indicated a predominantly random-coil structure (2% helical, 25% beta-structure) across calcium concentrations, while calcium binding increased intrinsic tryptophan fluorescence by 10% (Kd = 1 mM).

Cite This Study

Ohnishi et al. (1987) studied this question.

synapsesocial.com/papers/6a8505eed19b8ef3405b61fb https://doi.org/10.1021/bi00397a039

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Implication

Biochemical analysis demonstrates calcium-binding and structural properties of calsequestrin in rabbit muscle, suggesting specialized ion storage roles.

Fragmentation of rabbit skeletal muscle calsequestrin: spectral and ion-binding properties of the carboxyl-terminal region

Discussion

Member takes

Implication

Key Points

Cite This Study

Fragmentation of rabbit skeletal muscle calsequestrin: spectral and ion-binding properties of the carboxyl-terminal region

Discussion

Member takes

Implication

Key Points

Cite This Study

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