ISSN:
1435-1536
Keywords:
ADP/ATP carrier
;
loopstructure
;
substrate binding site
;
SH-reagent
;
mitochondria
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The transport mechanism of the bovine heart mitochondrial ADP/ATP carrier was studied using submitochondrial particles. The modifications of the cysteine residues of the carrier by the SH-reagents eosin-5-maleimide (EMA) andN-ethylmaleimide (NEM), and disulfide bond formation between these cysteine residues catalyzed by copper-o-phenanthroline (Cu(OP)2) under various conditions were studied. In particular, the effects of the transport inhibitors carboxyatractyloside (CATR) and bongkrekic acid (BKA), and fluorescein derivatives were examined. From the results, the topology of the carrier in the membrane, dynamic translocations of the loops of the carrier, and the structure of the primary binding site of the transport substrates ADP and ATP were deduced. The loops are concluded to act as both gates in the transport and binding sites for the substrates. Based on the results, a cooperative swinging-loop model is postulated as the transport mechanism of the ADP/ATP carrier.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01189519
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