Determination of dissociation constants between polyelectrolytes and proteins by affinity capillary electrophoresis
Författare
Summary, in English
In this manuscript we report the binding affinity between two model proteins, human serum albumin (HSA) and ribonuclease A (RNase A), and negatively charged polyelectrolytes, two different heparin fractions and dextran sulfate, by means of partial filling and affinity capillary electrophoresis. The apparent dissociation constants, Kd, obtained by use of the partial-filling method, between HSA and heparin (17 kDa), heparin (3 kDa) and dextran sulfate (8 kDa) were 33 and 307 μM, respectively. A new method was developed to determine affinities that take in account different migration directions between the protein and the polyelectrolyte, which was required to study RNase A. By use of this affinity capillary electrophoresis two Kd values were observed for the interaction between RNase A and heparin 17 kDa, yielding a high affinity binding with Kd1 0.0075 μM, and a lower affinity binding with Kd2 8.7 μM. For dextran sulfate 8 kDa these Kd values were 0.027 and 10.4 μM, respectively. Heparin 3 kDa only showed a single Kd value of 0.52 μM. The results show that the magnitude of the binding affinity depends on the type of polyelectrolyte and its molecular weight.
Avdelning/ar
Publiceringsår
2009-04-01
Språk
Engelska
Sidor
892-896
Publikation/Tidskrift/Serie
Journal of Chromatography. B
Volym
877
Issue
10
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Medical Engineering
Nyckelord
- dissociation constant
- heparin
- dextran sulfate
- human serum albumin
- capillary electrophoresis
- ribonuclease A
- RNase
- affinity binding
- partial filling
- polyelectrolytes
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1873-376X