Submitochondrial localization

Jullig, M. Eriksson, S. Mitochondrial and submitochondrial localization of human deoxyguanosine kinase. Eur. J. Biochem., 267, 5466-5472 (2000)... 

Okamoto H, Yamamoto S, Nozaki M, Hayashi O (1967) On the submitochondrial localization of L-Kynurenine-3-hydroxylase. Biochem Biophys Res Commun 26 309-314... 

Daae, L.N.W. Bremer, J. 1976) Biochim. Biophys. Acta, 210, 92-104. The aeylation of glycerophosphate in rat liver. A new assay procedure for glycerophosphate acylation, studies on its subcellular and submitochondrial localization and determination of the reaction products. 

I. Mitchell, J.R.D. Saggerson, E.D. (1994)/nt. J. Biochem., 26, 181-187. A study of glycerolphosphate acyltransferase in rat liver mitochondria-submitochondrial localization and some properties of the solubilized enzyme. 

To determine protein submitochondrial localization of proteins, either hypotonic lysis, which preferentially disrupts the mitochondrial outer membrane, or selective solubilization with digitonin are used. The digitonin method is based on the observation that digitonin preferentially extracts cholesterol, which is more prevalent in the mitochondrial outer membrane (Parsons and Yano, 1967). Low amounts of digitonin make holes in the outer membrane, thus releasing proteins from the intermembrane space. 

At this time the evidence that hyperoxic-induced lung injury was due to excessive oxygen free radical production was still largely indirect. The next major event which specifically addressed this question was the important experiments of Crapo and colleagues in the early 1980 s [10]. These studies conducted with lung tissue were similar to those performed earlier in liver [11] and heart [12]. Crapo and co-workers found that superoxide production, measured as CN-insensitive respiration, was increased in lung slices when exposed to 100% O2 rather than air [10]. This work was extended to the measurement of O2 production in submitochondrial particles [13]. Clearly then exposure of tissues to elevated concentrations of O2 leads to ROS production, the extent of which, in association with local antioxidant defences, will determine the redox balance of the tissue. 

It is quite clear that for mitochondria, where is localized within the vesicle, a jump-like pH increase can lead to only one elementary act, that indeed was observed in [182]. In this case the component of the ATP-synthase is faced inside the vesicle and, thus, according to Fig. 5.27, the state 5 state 1 transition becomes impossible. Only a single act of the AH ionization would take place after the pH jump due to a passive leakage of protons via the mitochondrial membrane. Otherwise, for submitochondrial particles turned inside-out [21] a multiple ATP synthesis after the pH increase is achieved by means of the reiteration of the proton cycle. According to the model considered above, the transmembrane electrochemical gradient of protons plays the role of an extensive but not intensive factor [190,191]. Its increase (or decrease) changes the number of elementary acts of ATP synthesis which can be performed, until the condition formulated above for the elementary act ceases to be fulfilled. 

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