Three different approaches for the clarification of the interactions between lipoproteins and chondroitin-6-sulfate

KATRIINA LIPPONEN; PATRICIA W. STEGE; GERALDINE CILPA; JÖRGEN SAMUELSSON; TORGNY FORNSTEDT; MARJA-LIISA RIEKKOLA

ANALYTICAL CHEMISTRY

AMER CHEMICAL SOC

Año: 2011 vol. 83 p. 6040 - 6046

0003-2700

Two different experimental approaches were used for obtaining a comprehensive view andunderstanding of the interactions between apolipoprotein B-100 (ApoB-100) of low-densitylipoprotein and apolipoprotein E (ApoE) of high-density lipoprotein and chondroitin-6-sulfate(C6S) of arterial proteoglycan. The techniques employed were partial filling affinity capillaryelectrophoresis (PF-ACE) and continuous quartz crystal microbalance (QCM). In addition,molecular dynamic (MD) simulations were used to provide a supportive visual insight into theinteraction mechanism. A new tool for analysis of QCM-data was utilized, i.e. adsorption energydistribution calculations, which allowed a deeper understanding of the interactions, especially atdifferent temperatures. The PF-ACE technique probed mainly the strong adsorption interactionswhereas in the MD calculations short and long-range interactions could be distinguished. Althoughthere are differences in the techniques a pretty good agreement was achieved between the threeapproaches for the interaction of 15 amino acid peptide of ApoE with C6S giving affinity constantsof 4.66 by QCM, 5.02 by PF-ACE and 7.39 by MD, and for 19 amino acid peptide of ApoB with C6S 5.34 by QCM, 5.28 by PT-ACE and 4.60 by MD at physiological temperature 37.0 oC.