Analytical Ultracentrifugation Center

The Analytical Ultracentrifugation Lab is a research facility of the Biomedical Department at the Campus Drie Eiken of the University of Antwerp. The head of the faculity is Prof. Peter De Deyn. The contact person is Ing. Tony Aerts.

Techniques used

Our lab has a Beckman XLA - Analytical Ultracentrifuge ( AUC), equipped with scanning absorption optics (= from 190 to 800 nm). The temperature range is between 2°C and 37°C.

Sedimentation Equilibrium

By using this method, we can measure the molecular weight of the solute at one solute concentration. Using different concentrations of the solute we can have an idea of self-interaction or non-ideality. In this way we can calculate the association constant ( if there is one). Up to 7 samples can be analysed simultaneously.For the best results, we ask :

150 microliter solution of a concentration between 0.1 and 0.4 OD.Samples must be dialysed against the selected buffer, which should be free of absorbing components in the choosen wavelength range.We also need the extinction coefficient of a 1% solution of solute at the used wavelength.If known the partial specific volume is also important. 

Sedimentation Velocity

By using this method we can measure the sedimentation coefficient of the solute. This method will tell us something about the heterogeneity of the sample. For the best results we ask: 350 microliter solution with a concentration between 0.5 and 1 OD.

Publications

1) Coopman S.,De Block J., Aerts T., Peeters W.,Moens L. and Clauwaert J , ”Physical chemical studies on bovine eye lens proteins.II. Comparative physical study of the low-moleculair-weight alpha-crystallin from calf lens cortical and nuclear fiber cells”, in Exp.Eye Res. (1984) 38:463-476.,93,BP13.

2) Aerts T., Xia J.Z., Slegers H., De Block J. en Clauwaert J.,”Hydrodynamic characterization of the major intrinsic protein (MIP) extracted from the bovine lens fiber membranes in n-octyl-beta-D-glucopyranoside: evidence for a tetrameric structure “ , in J.Biol.Chem.(1990) 265,8675-8680.

3) Xia J.Z., Aerts T., Donceel K. and Clauwaert J.,” Light scattering by Bovine alpha crystallin proteins  in solution: Hydrodynamic structure and interparticle interaction”, in Biophysical Journal (1994) 66, 861-872.

4) Aerts T., Wang Q., Tatarkova S. and Clauwaert J.,”Physical chemical characterization of the different individuel cortical alpha-crystallin fractions from bovine lenses “ in Progr.Colloid Polym.Sci (1995) 99, 94-100.

5) Vanhoudt J., Aerts T., Abgar S. and Clauwaert J.,”Quaternaire structure and interaction parameters of bovine alpha-crystalline: influence of isolation conditions” in Progr.Colloid.Polym. Sci (1997) 107:88-93.

6) Vanhoudt J., Aerts T., Abgar S. and Clauwaert J.,” Quaternary structure of bovine alpha-crystalline : influence of temperature”, in International Journal of Biological Macromolecules  (1998) 22, 229-237.

7) Abgar S, Vanhoudt J., Aerts T. and Clauwaert J.,”Study of the chaperoning mechanism of bovine lens alpha-crystallin, a member of the alpha-small heat shock superfamily”, Biophys J., 2001 Apr;80(4):1986-95.

8) Abgar S, Yevlampieva N., Aerts T., Vanhoudt J. and Clauwaert J.,”Chaperone-like activity of Bovine Lens alpha-crystallin in the presence of dithiothreitol-destabilized proteins: characterization of the formed complexes”, BBRC,2000,vol 276,N:2,619-625.

9) Vanhoudt J., Abgar S., Aerts T. and Clauwaert J., “ Native Quaternary structure of Bovine Alpha-crystallin”, Biochemistry,2000,vol39,n:15,p4483-4492.

10) Abgar S., Backmann J., Aerts T., Vanhoudt J. and Clauwaert J. , “ The structural differences between bovine lens aA- and aB-crystallin.” In Eur.J. Biochemistry, 2000, 267,5916-5925.

11) Dewilde S, Kiger L, Burmester T, Hankeln T, Baudin-Creuza V, Aerts T, Marden MC, Caubergs R, Moens L., ” Biochemical characterization and ligand binding properties of neuroglobin, a novel member of the globin family.” In J Biol Chem. 2001 Oct 19;276(42):38949-55.

12) Filee P, Vreuls C, Herman R, Thamm I, Aerts T, De Deyn PP, Frere JM, Joris B., ” Dimerization and DNA binding properties of the Bacillus licheniformis 749/I BlaI repressor.” In J Biol Chem. 2003 May 9;278(19):16482-7.

13) Vreuls C, Filee P, Van Melckebeke H, Aerts T, De Deyn P, Llabres G, Matagne A, Simorre JP, Frere JM, Joris B.” Guanidinium chloride denaturation of the dimeric Bacillus licheniformis BlaI repressor highlights an independent domain unfolding pathway.” In Biochem J. 2004 Nov 15;384(Pt 1):179-90.

Neuronal Circuit Research

Addressing the specific research interests of the laboratory requires a multidisciplinary approach. Part of the research team's expertise and equipment is listed below.

Equipment for electrophysiology

Four high-resolution patch-clamp setups for analyzing  primary cell cultures or transiently/stably transfected cell lines, 2 of the setups are equipment with a pressurized fast-switching perfusion system for administering drugs/toxins.  

One cut-open vaseline gap oocyte setup able to perform state-of-the-art voltage-clamp fluorometry (VCF) experiments.  

Molecular biology and biochemistry techniques

Laboratory has a large collection of ion channel clones (mainly Kv channels) and the standard molecular biology equipment for cloning new channels or creating channel mutations.

Cell culture and expression systems

L2 cell culture facility equipped with two laminar flow hoods and 4 CO2 incubators. Common cell lines for heterologous expression of proteins (e.g. HEK293, CHO, Ltk-,…) are part of our routine cell culture repertoire. Cells can be transiently or stably transfected according to the experimental needs.

Facility to express channel proteins in Xenopus laevis oocytes (e.g. for performing VCF experiments).