Biomolecules in a spin

Analytical ultracentrifugation     

D Scott, S E Harding and A J Rowe (eds)   

Cambridge, UK: Royal Society of Chemistry  2006 | 580pp | ?99.95 (HB) | ISBN 0854045473 

Reviewed by Jayesh Gor

This is a hefty book with a hefty price tag and a hefty number of mathematical equations throughout. So why would a novice coming into this field with a biological background buy it? Well for starters, it would be useful for any group or department that has an analytical ultracentrifuge (AUC), or has an interest in one. 

Those people with little knowledge of mathematics need not fear. The authors have done an excellent job in explaining what the equations mean and their relevance. On top of this they have translated them into nice little computational algorithms and written programmes which handle all the calculations at the click of a mouse button. So simple that even a novice can handle the data analysis.  

So what does an analytical ultracentrifuge do? A quick perusal of the book and I see that the machine is capable of tracking the sedimentation of macromolecules in a solvent. So what? 

The AUC is used to study proteins, DNA, polysaccharides, membrane proteins, polymers, colloids and nanoparticles. The AUC can tell you if the molecules in solution are homogeneous, multimeric or have multi components. You can calculate the molecular weight, the distribution of molecular species and the affinities between them. You can estimate the rough size and shape of molecules. All this and you can even get your molecules back. 

I expect you would normally shove your molecules through gels, vapourise them for mass spectrometry or fire x-rays and neutrons at them. Try getting all your molecules back after that! AUC can even identify oligomers of macromolecules which other techniques cannot see. It can identify protein conformations in solution that crystal structure will not allow. 

This book is essential for planning a sedimentation velocity or equilibrium experiment. The chapters are sensibly laid out with a general introduction to centrifugation, description of the thermodynamic behaviour of molecules in solution, and description of software packages for data analysis. It is brimming with very useful advice. A must for all biochemists and biophysicists.