Preparing Protein Microarrays by Soft-Landing of Mass-Selected Ions
Zheng Ouyang,1
Zoltán Takáts,1
Thomas A. Blake,1
Bogdan Gologan,1
Andy J. Guymon,1
Justin M. Wiseman,1
Justin C. Oliver,2
V. Jo Davisson,2
R. Graham Cooks1*
Intact, multiply protonated proteins of particular mass and charge were selected from ionized protein mixtures and gently landed at different positions on a surface to form a microarray. An array of cytochrome c, lysozyme, insulin, and apomyoglobin was generated, and the deposited proteins showed electrospray ionization mass spectra that matched those of the authentic compounds. Deposited lysozyme and trypsin retained their biological activity. Multiply charged ions of protein kinase A catalytic subunit and hexokinase were also soft-landed into glycerol-based liquid surfaces. These soft-landed kinases phosphorylated LRRASLG oligopeptide and D-fructose, respectively.
1 Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
2 Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA.
* To whom correspondence should be addressed. E-mail: cooks{at}purdue.edu
