Application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for monitoring the digestion of phosphatidylcholine by pancreatic phospholipase A2

Author: Petkovic´ M.   Mu¨ller J.   Mu¨ller M.   Schiller J.   Arnold K.   Arnhold J.  

Publisher: Elsevier

ISSN: 0003-2697

Source: Analytical Biochemistry, Vol.308, Iss.1, 2002-09, pp. : 61-70

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Different methods were established for monitoring the phospholipaseA2(PLA2)activity but all of them are rather cumbersome and time consuming. In this paper we have investigated the suitability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the determination of the PLA2activity. Phosphatidylcholine (PC) was digested with pancreaticPLA2 under different conditions, i.e., variousCa2+, PC, andPLA2 concentrations. The digestion products were analyzed by MALDI-TOF MS and the concentration of lysophosphatidylcholine (LPC)—generated uponPLA2 digestion—was determined by the application of an internal standard (known concentration) and by a comparison of their signal-to-noise ratios. The results clearly demonstrate that the LPC concentration determined from the MALDI-TOF mass spectra correlates directly with the activity of the applied enzyme. Additionally, LPC concentration increased with an increase inCa2+, as well as in the PC concentration. A single MALDI-TOF mass spectrum provides immediate information on the digestion products as well as on the residual substrate without requirements for any previous derivatization. MALDI-TOF MS can be easily and simply applied for monitoring thePLA2 activity and we assume that this method might also be useful for other types of phospholipases.© 2002 Elsevier Science (USA)

Related content