Mapping of functional domains in the plasma membrane Ca2+ pump using trypsin proteolysis.
The purified erythrocyte Ca2+ pump has been exposed to trypsin under conditions designed to enrich the fragments of molecular mass 90, 85, 81, and 76 kDa, respectively. In SDS-polyacrylamide gels, these fragments are accompanied by a product of molecular mass about 33 kDa. N- and C-terminal sequencing of the fragments blotted on PVDF membranes has located the four high molecular mass fragments and the 33-kDa fragment within the pump structure. The work has extended previous work on the organization of the calmodulin-interacting domain of the pump (Zurini et al., 1984; Benaim et al., 1984) and has tentatively placed the domain of the pump which interacts with acidic phospholipids between transmembrane helices 2 and 3.
Zvaritch
E
E
Laboratory for Biohemistry, Swiss Federal Institute of Technology (ETH), Zurich.
James
P
P
Vorherr
T
T
Falchetto
R
R
Modyanov
N
N
Carafoli
E
E
D000595:Amino Acid Sequence; D001665:Binding Sites; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000201:enzymology; D006801:Humans; D008563:Membrane Lipids / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis; D010743:Phospholipids / Q000378:metabolism; D011487:Protein Conformation; D006180:Proton-Translocating ATPases / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics; D014357:Trypsin
D002147:Calmodulin; D008563:Membrane Lipids; D008565:Membrane Proteins; D010446:Peptide Fragments; D010743:Phospholipids; D014357:Trypsin; D006180:Proton-Translocating ATPases; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase