Enzymatic Properties of the Inner and Outer Membranes of Rat Liver Mitochondria
نویسندگان
چکیده
Treatment of rat liver mitochondria with digitonin followed by differential centrifugation was used to resolve the intramitochondrial localization of both soluble and particulate enzymes. Rat liver mitochondria were separated into three fractions: inner membrane plus matrix, outer membrane, and a soluble fraction containing enzymes localized between the membranes plus some solublized outer membrane. Monoamine oxidase, kynurenine hydroxylase, and rotenone-insensitive NADH-cytochrome c reductase were found primarily in the outer membrane fraction. Succinate-cytochrome c reductase, succinate dehydrogenase, cytochrome oxidase, beta-hydroxybutyrate dehydrogenase, alpha-ketoglutarate dehydrogenase, lipoamide dehydrogenase, NAD- and NADH-isocitrate dehydrogenase, glutamate dehydrogenase, aspartate aminotransferase, and ornithine transcarbamoylase were found in the inner membrane-matrix fraction. Nucleoside diphosphokinase was found in both the outer membrane and soluble fractions; this suggests a dual localization. Adenylate kinase was found entirely in the soluble fraction and was released at a lower digitonin concentration than was the outer membrane; this suggests that this enzyme is localized between the two membranes. The inner membrane-matrix fraction was separated into inner membrane and matrix by treatment with the nonionic detergent Lubrol, and this separation was used as a basis for calculating the relative protein content of the mitochondrial components. The inner membrane-matrix fraction retained a high degree of morphological and biochemical integrity and exhibited a high respiratory rate and respiratory control when assayed in a sucrose-mannitol medium containing EDTA.
منابع مشابه
THE S U B M I T O C H O N D R I A L LOCALIZATION OF MONOAMINE OXIDASE An Enzymatic Marker for the Outer Membrane of Rat Liver Mitochondria
Controlled osmotic lysis (water-washing) of rat liver mitochondria results in a mixed population of small vesicles derived mainly from the outer mitochondrial membrane and of larger bodies containing a few cristae derived from the inner membrane. These elements have been separated on Ficoll and sucrose gradients. The small vesicles were rich in monoamine oxidase, and the large bodies were rich ...
متن کاملCharacterization of biophysical properties of single chloride channel in rat brain mitochondrial inner membrane by channel incorporation into bilayer lipid membrane
Introduction: Recent studies have shown the presence of Cl- channels in heart and liver mitochondrial membranes. In this work, we have characterized the functional profile of a Cl- channel from rat brain mitochondria. Methods: After removing and homogenizing the rat brain, the supernatant was separately centrifuged in MSEdigitonin, H2O and Na2CO3 and mitochondrial inner membrane vesicles wer...
متن کاملTurnover of outer and inner membrane proteins of rat liver mitochondria.
Recent reports on the properties and composition of outer and inner mitochondrial membranes suggest that outer and inner membranes of mitochondria are derived from different sources of the cell [l-3]. In vitro experiments [4-61 indicate that the protein synthesizing system of isolated rat liver mitochondria contributes only to the synthesis of the inner and not to that of the outer mitochondria...
متن کاملFractionation of human liver mitochondria: enzymic and morphological characterization of the inner and outer membranes as compared to rat liver mitochondria.
The fractionation of human liver mitochondria into inner membrane, outer membrane and matrix material is reported. Compared with rat, human liver mitochondria are more fragile. Fractionation can be achieved in only 2 steps, a digitonin treatment for removal of the outer membrane and centrifugation of the inner membrane plus matrix particles through a linear sucrose gradient resulting in purifie...
متن کاملBiophysical properties of single potassium channel in the brain mitochondrial inner membrane of male rat with Alzheimer’s disease
Introduction: Alzheimer’s disease is a progressive neurodegenerative disorder, characterized by impairment of memory and changes in behavior and personality. Recent evidence suggests that mitochondrial channels play important roles in memory disorders. Accordingly, the biophysical properties of a single potassium channel were investigated in the brain mitochondrial inner membrane of rat with...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of Cell Biology
دوره 38 شماره
صفحات -
تاریخ انتشار 1968