MALDI-TOF High Mass Calibration up to 200 kDa Using Human Recombinant 16 kDa Protein Histidine Phosphatase Aggregates

Background: Protein histidine phosphatase (PHP) is an enzyme which removes phosphate groups from histidine residues. It was described for vertebrates in the year 2002. The recombinant human 16 kDa protein forms multimeric complexes in physiological buffer and in the gas phase. High-mass calibration...

Authors: Ludwig, Katrin
Habbach, Mohamed Schähdi
Krieglstein, Josef
Klumpp, Susanne
König, Simone
Division/Institute:FB 05: Medizinische Fakultät
FB 12: Chemie und Pharmazie
Document types:Article
Media types:Text
Publication date:2011
Date of publication on miami:19.02.2013
Modification date:16.04.2019
Edition statement:[Electronic ed.]
Source:PLoS ONE 6 (2011) 8, e23612
DDC Subject:610: Medizin und Gesundheit
License:CC BY 2.5
Language:English
Notes:Finanziert durch den Open-Access-Publikationsfonds 2011/2012 der Deutschen Forschungsgemeinschaft (DFG) und der Westfälischen Wilhelms-Universität Münster (WWU Münster).
Format:PDF document
URN:urn:nbn:de:hbz:6-97379389900
Permalink:http://nbn-resolving.de/urn:nbn:de:hbz:6-97379389900
Other Identifiers:DOI: doi:10.1371/journal.pone.0023612
Digital documents:journal.pone.0023612.pdf

Background: Protein histidine phosphatase (PHP) is an enzyme which removes phosphate groups from histidine residues. It was described for vertebrates in the year 2002. The recombinant human 16 kDa protein forms multimeric complexes in physiological buffer and in the gas phase. High-mass calibration in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has remained a problem due to the lack of suitable standards. Large proteins can hardly be freed of their substructural microheterogeneity by classical purification procedures so that their use as calibrants is limited. A small adduct-forming protein of validated quality is a valuable alternative for that purpose. Methodology/Principal Findings: Three major PHP clusters of ,113, 209 and .600 kDa were observed in gel filtration analysis. Re-chromatography of the monomer peak showed the same cluster distribution. The tendency to associate was detected also in MALDI-TOF MS measuring regular adducts up to 200 kDa. Conclusions/Significance: PHP forms multimers consisting of up to more than 35 protein molecules. In MALDI-TOF MS it generates adduct ions every 16 kDa. The protein can be produced with high quality so that its use as calibration compound for high mass ranges above 100 kDa, where standards are difficult to obtain, is feasible.