Analysis of the conformation and ligand-binding properties of the activation segment of pig procarboxypeptidase A.
The isolated activation segment of pig procarboxypeptidase A binds two Tb3+ ions in a strong and specific way. In contrast, the binding of Ca2+, Cd2+ and Mg2+ is weak. The binding of Tb3+ increases the resistance of the isolated activation segment against proteolysis and competes for the binding of the carbocyanine dye Stains-All. This dye forms complexes with the activation segment showing spectral properties similar to those observed with EF-hand structures. The presented results support a previous hypothesis on the existence of two regions in the activation segment of pancreatic procarboxypeptidases structurally related to Ca2+-binding domains of the EF-hand protein family.
Vilanova
M
M
Departament de Bioquimica i Biologia Molecular (Unitat de Ciències), Universitat Autònoma de Barcelona, Spain.
Vendrell
J
J
Cuchillo
C M
CM
Avilés
F X
FX
D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002232:Carbocyanines; D002268:Carboxypeptidases / Q000378:metabolism*; D043422:Carboxypeptidases A; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism*; D008024:Ligands; D046911:Macromolecular Substances; D011487:Protein Conformation; D013053:Spectrophotometry; D013194:Staining and Labeling; D013552:Swine; D013725:Terbium / Q000378:metabolism; D014357:Trypsin
D002232:Carbocyanines; D004792:Enzyme Precursors; D008024:Ligands; D046911:Macromolecular Substances; D013725:Terbium; C012040:stains-all; D002268:Carboxypeptidases; D043422:Carboxypeptidases A; D014357:Trypsin; D002118:Calcium