Properties of energy-dependent calcium transport by rat liver microsomal fraction as revealed by initial-rate measurements
| Autor: | F L Bygrave |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
Carbonyl Cyanide m-Chlorophenyl Hydrazone
Ruthenium red Proton Analytical chemistry Biological Transport Active chemistry.chemical_element In Vitro Techniques Calcium Biochemistry Micrometre Valinomycin chemistry.chemical_compound Adenosine Triphosphate Phase (matter) Animals Magnesium Electrochemical gradient Molecular Biology Cell Biology Ruthenium Red Rats Kinetics chemistry Microsomes Liver Biophysics Microsome Trialkyltin Compounds Research Article |
| Zdroj: | Biochemical Journal. 170:87-91 |
| ISSN: | 0264-6021 |
| DOI: | 10.1042/bj1700087 |
| Popis: | Measurements of the initial rate of Ca2+ transport by rat liver microsomal preparations reveal the existence of two phases of transport activity. The first, a phase of rapid transport, is complete by 3-5 min, at which time the second (slower) phase begins; this remains linear for up to at least 40 min. The initial phase is minimal in the absence of MgATP. The initial rate of Ca2+ transport reaches values as high as 25 nmol/min per mg of protein; the Km for Ca2+total is 1-2 micrometer and that for MgATPtotal about 500 micrometer. Ruthenium Red (3-5 nmol/mg of protein) has little effect on the initial rate of transport, whereas tributylin (2 micrometer) inhibits equally in a KC1- or a KNO3-containing medium. Compunds that collapse components of the proton electrochemical gradient in mitochondria (valinomycin and carbonyl cyanide m-chlorophenylhydrazone) each inhibit by 70-80% the initial rate of microsomal Ca2+ transport. |
| Databáze: | OpenAIRE |
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