Structural analysis of the isolated chloroplast coupling factor and the N,N'-dicyclohexylcarbodiimide binding proteolipid.
Negative staining of purified spinach dicyclohexylcarbodiimide (DCCD) sensitive ATPase revealed a population of 110 A subunits attached by stalks to short string-like aggregates. The interpretation of these data is that 110 A CF1 are attached by stalks to an aggregate of CF0. The CF1-CF0 complex was incorporated into phospholipid vesicles; freeze-fracture analysis of this preparation revealed a homogeneous population of particles spanning the lipid bilayer; those averaged 96 A in diameter. The DCCD binding proteolipid (apparent molecular weight 7500), an integral component of CF0, was isolated from membranes by butanol extraction and was incorporated into phospholipid vesicles. Freeze-fracture analysis of the DCCD-binding proteolipid/vesicle preparation revealed a population of particles averaging 83 A in diameter suggesting that the DCCD-binding proteolipid self-associates in lipid to form a stable complex. This complex may be required for proton transport across chloroplast membranes in vivo. The size difference between CF0 and DCCD-proteolipid freeze-fracture particles may be related to differences in polypeptide composition of the two complexes.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D002234:Carbodiimides; D004024:Dicyclohexylcarbodiimide; D005614:Freeze Fracturing; D007425:Intracellular Membranes / Q000201:enzymology; D007700:Kinetics; D008051:Lipid Bilayers; D008970:Molecular Weight; D010944:Plants / Q000201:enzymology; D011485:Protein Binding; D011510:Proteolipids / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*
D002234:Carbodiimides; D008051:Lipid Bilayers; D011510:Proteolipids; D004024:Dicyclohexylcarbodiimide; D000251:Adenosine Triphosphatases; D006180:Proton-Translocating ATPases