Anomalous electrophoretic behavior of a very acidic protein: ribonuclease U2.
Ribonuclease U2 is a low-molecular-weight acidic protein with three disulfide bridges. This protein displays an anomalous electrophoretic behavior on standard SDS-PAGE. The electrophoretic mobility of the nonreduced protein roughly corresponds to its molecular mass while the migration of the reduced protein would be in accordance with the expected molecular mass of the protein dimer. This study reveals that the protein does not bind SDS under the SDS-PAGE conditions, its electrophoretic mobility being only determined by its electrostatic charge and hydrodynamic properties. In addition, the nonreduced protein cannot be blotted to a membrane. Unfolding of the protein upon reduction of its disulfide bridges enables electrotransference to membranes due to a restricted diffusion along the electrophoresis gel.
García-Ortega
Lucía
L
Departamento de Bioquímica y Biología Molecular I, Facultad de Química, Universidad Complutense, Madrid, Spain.
De los Ríos
Vivian
V
Martínez-Ruiz
Antonio
A
Oñaderra
Mercedes
M
Lacadena
Javier
J
Martínez del Pozo
Alvaro
A
Gavilanes
José G
JG
D000595:Amino Acid Sequence; D015153:Blotting, Western; D002942:Circular Dichroism; D004220:Disulfides / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D004722:Endoribonucleases / Q000737:chemistry / Q000302:isolation & purification*; D006358:Hot Temperature; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010720:Phosphines / Q000737:chemistry; D011485:Protein Binding; D011489:Protein Denaturation; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry
D004220:Disulfides; D004722:Endoribonucleases; D010720:Phosphines; D012967:Sodium Dodecyl Sulfate; C080938:tris(2-carboxyethyl)phosphine; C022544:ribonuclease U2