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Dokumenttyp:
Zeitschriftenaufsatz 
Autor(en):
Gebhardt, R.; Toro-Sierra, J.; Kulozik, U. 
Titel:
Pressure Dissociation of ß-Lactoglobulin Oligomers near its Isolelectric Point // Pressure dissociation of \textgreek{b}-lactoglobulin oligomers near their isoelectric point 
Abstract:
We study pressure dissociation of aggregated states of b-lactoglobulin at pH 4.6 using static and dynamic light scattering. We find that octamers dissociate at 20 °C into dimers at pressures P < 100 MPa and into monomers at P < 200 MPa. The dimer--monomer dissociation equilibrium at T 1/4 20 °C is reversible. The dodecamer--dimer equilibrium is quasi-reversible since aggregation occurred after decompression from 30 MPa back to ambient pressure. The corresponding molar volume difference is DV 1/4 101 ml mol*l for the octamer--dimer and DV 1/4 276 ml mol * l for the dimer--monomer transition. The calculated free energy of association for the dimers at atmospheric pressure is DG 1/4 59.3 kJ 1 1 mol * l and for the monomers is DG 1/4 59.8 kJ mol * l. The high pressure dissociation is not emphasized 1/4 by lowering the temperature. Instead, the quaternary structure of ß-lactoglobulin at T 1/4 10 °C remains unchanged up to pressures of P 1/4 180 MPa followed by aggregation at pressures P > 180 MPa. 
Zeitschriftentitel:
Soft Matter 
Jahr:
2012 
Band / Volume:
Heft / Issue:
46 
Seitenangaben Beitrag:
11654--11660 
Print-ISSN:
1744-683X