ELECTROSPRAY MASS-SPECTROMETRIC ANALYSIS OF POLY(ETHYLENE GLYCOL)-PROTEIN CONJUGATES

Proteins immobilized on polymer supports are extensively used to devel op bioanalytical methods and the determination of the protein/polymer molar ratio is important both for quantifying the catalytic activity a nd calculating the diffusion rate of the substrates, In this paper a m ethod, based on electrospray mass spectrometry, for characterizing sub tilisin and lipase immobilized on chemically modified poly(ethylene gl ycol)-5000 is described, The results obtained show that this technique is particularly effective, The information provided by it can be used to optimize the synthesis of these polymer-protein conjugates as well as to evaluate the efficiency of their separation and purification. ( C) 1997 by John Wiley & Sons, Ltd.