Participation of a non-covalent phosphointermediate in ATP hydrolysis by the sarcoplasmic reticulum Ca2(+)-cotransport ATPase.
With increasing SDS/protein ratios, covalent phosphorylation by ATP and Pi is abolished before ATP hydrolysis (Pi production) ceases. We have shown that the SDS-dependent profiles of the decline in covalent phosphorylation by either substrate are virtually identical, reflecting a common mechanism of detergent interaction, while ATP can be hydrolysed via a non-covalent phosphointermediate. Our studies support that the transfer of both terminal Pi from ATP, as well as Pi to its final binding site, is a multistep reaction involving electrostatic interaction with one or more amino acid side chains, including a Lys residue.
Fassold
E
E
Max-Planck-Institut für Medizinische Forschung, Abteilung für Physiologie, Heidelberg, Federal Republic of Germany.
Hasselbach
W
W
Küchler
B
B
D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000502:physiology*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D006868:Hydrolysis; D008239:Lysine / Q000737:chemistry; D010750:Phosphoproteins / Q000096:biosynthesis; D010766:Phosphorylation; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*
D002135:Calcium-Binding Proteins; D010750:Phosphoproteins; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases; D008239:Lysine; D002118:Calcium