Analysis of Dolichols and Polyprenols and Their Derivatives by Electron Impact, Fast Atom Bombardment and Electrospray Ionization Tandem Mass Spectrometry

Abstract

Dolichols and polyprenols are polyisoprenoid lipids found in all cells. Polyisoprenoids have recently been found covalently bound to cellular proteins constituting a new type of post-translational modification. To study these compounds effectively in biological systems a sensitive mass spectrometric procedure giving molecular weight and structural information is required. In the present study an assessment has been made of possible mass spectrometric procedures. Dolichols and polyprenols have been analysed at the pmol level in their underivatized form and as tert-butyldimethylsilyl ethers by electron ionization mass spectrometry. Sulphated dolichols and polyprenols have been analysed at a pmol level by fast-atom bombardment and at the sub-pmol level by electrospray mass spectrometry. Dolichol phosphates have also been analysed by electrospray mass spectrometry. Collision-induced dissociation spectra of the underivatized and derivatized polyisoprenoids have been recorded. These spectra provide structural information from only pmols of sample.