Calcium Binding and Tension Development in Detergent-Treated Muscle Fibers
| Autor: | M. Orentlicher, Philip W. Brandt, Harry Grundfest, John P. Reuben |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1974 |
| Předmět: |
Physiology
Kinetics Detergents chemistry.chemical_element Stimulation Astacoidea Calcium In Vitro Techniques Models Biological Article Myofibrils medicine Animals Fiber Diminution Binding Sites Endoplasmic reticulum Muscles Sarcoplasmic Reticulum chemistry Biochemistry Biophysics medicine.symptom Myofibril Muscle contraction Deoxycholic Acid Muscle Contraction |
| Zdroj: | The Journal of General Physiology |
| ISSN: | 1540-7748 0022-1295 |
| Popis: | The nonionic detergent Brij 58 eliminates irreversibly the capability of the sarcoplasmic reticulum (SR) of skinned crayfish muscle fibers to sequester Ca and to release it under appropriate stimulation. In contrast to deoxycholate (DOC) which causes an irreversible diminution of tension as well, Brij 58 does not affect the contractile proteins. Comparison of the time-course of tension development before and after Brij treatment demonstrates that Ca is accessible to the contractile proteins more rapidly after the SR is destroyed but, nevertheless, much more slowly than is predicted for free diffusion of Ca in the myoplasm. Slowing apparently results because of the presence of ca 1 mmol/kg fiber of myoplasmic Ca-binding sites that remain after Ca uptake of the SR is eliminated. A theoretical model is presented which allows for the effects of binding sites and of an unstirred layer in the vicinity of the fiber on Ca diffusion into the myoplasm. |
| Databáze: | OpenAIRE |
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