MASS-SPECTROMETRY OF PEPTIDES AND PROTEINS BY MATRIX-ASSISTED ULTRAVIOLET-LASER DESORPTION IONIZATION

This chapter discusses mass spectrometry of peptides and proteins by matrix-assisted ultraviolet laser desorption/ionization. Three features make mass spectrometry an attractive analytical technique for biorganic molecules: very high sensitivity, potential for very highly accurate mass determination, and ability to elucidate structural information of the molecules under investigation. It is shown in this chapter that the goal of extremely high sensitivity has already been achieved in laser desorption/ionization (LDI-MS). It also yields important structural information—namely, on the level of the quaternary and, possibly, tertiary structures more than on that of the primary and secondary ones. The attainable accuracy in molecular mass determination still leaves much to be desired, but substantial improvements can be expected. Most lasers throughout the wavelength range from the far-ultraviolet to the far-infrared and with pulse durations from continuous wave down to the femtosecond (10-15 sec) range have at some point been used to irradiate solid or liquid material in vacuum or under ambient pressure with the intent to couple energy from the laser beam into the sample via linear or nonlinear absorption and to transfer some of the sample material into the gas phase, a prerequisite for a mass spectrometric analysis. © 1990, Elsevier Inc. All rights reserved.