Inorganic Pyrophosphatase of Rat Liver Mitochondria
نویسندگان
چکیده
Stimulation of Mg(2+)-dependent inorganic pyrophosphatase activity several fold by disruption of mitochondrial membranes does not appreciably alter the catalytic properties of the enzyme. Stimulation is due to increased accessibility of substrate to the enzyme, which is not solublized on activation. The enzyme is attached to the inside of the inner membrane, and under physiological conditions probably hydrolyzes only intramitochondrially-produced PP(i).
منابع مشابه
Metabolism of Inorganic Pyrophosphate. I. Microsomal Inorganic Pyrophosphate Phosphotransferase of Rat Liver.
The formation of large amounts of inorganic pyrophosphate as a by-product of numerous synthetic reactions in nearly all living tissues makes the metabolic reactions of this compound of interest. Rapid hydrolysis to orthophosphate is presumed to be the fate of most inorganic pyrophosphate but the possibility of the conservation and utilization of some of the energy of this compound has been a su...
متن کاملEvidence for the Common Identity of Glucose 6-phosphatase, Inorganic Pyrophosphatase, and Pyrophosphate-glucose Phosphotransferase.
The glucoseand inorganic pyrophosphate-dependent formation of glucose 6-phosphate has been demonstrated in mouse (1) and rat (2) liver mitochondrial preparations. The mouse mitochondrial enzyme catalyzing this reaction appears to be very closely related to an inorganic pyrophosphatasel activity found in such preparations (1). Recent studies2 have indicated that rat liver microsomes, which also ...
متن کاملSubcellular distribution of inorganic pyrophosphatase activity in various normal and neoplastic cell types.
Inorganic pyrophosphatase (PPiase) activity was measured in cell fractions of rat, mouse, and human erythrocytes; normal rat liver; Novikoff hepatoma; Morris 3924A hepatoma; and mouse Ehrlich and Sarcoma 37 ascites tumors. Despite high intracellular activities, when precautions were taken to maintain cell integrity, only negligible activities were found on the surface of intact erythrocytes, No...
متن کاملInhibition of mitochondrial-matrix inorganic pyrophosphatase by physiological [Ca2+], and its role in the hormonal regulation of mitochondrial matrix volume.
1. The pyrophosphatase activity in cytosolic and mitochondrial fractions of rat liver was 1.7 and 0.26 units/mg of protein respectively when assayed at 37 degrees C in the presence of physiological [Mg2+] (0.3 mM). 2. Approx. 80% of the mitochondrial pyrophosphatase was inaccessible to extramitochondrial PPi, of which 40% represented soluble matrix enzyme (0.38 unit/mg of matrix protein). 3. Ca...
متن کاملThe effect of 6-deoxyclitoriacetal from Clitoria macrophylla Wall. on rat liver mitochondrial respiration and ATPase activity
A Thai plant Clitoria macrophylla Wall. was claimed to possess some pharmacological activities. The phytochemical studies reported a rotenoid compound, 6-deoxyclitoriacetal, which exhibits the cytotoxic effect in several cell line experiments. This report was to study the effect of 6-deoxyclitoriacetal on rat liver mitochondria, which may associated to its cytotoxic phenomena. Mitochondrial sus...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of Cell Biology
دوره 42 شماره
صفحات -
تاریخ انتشار 1969