New strategies for characterizing ancient proteins using matrix-assisted laser desorption ionization mass spectrometry

Citation
Ph. Ostrom et al., New strategies for characterizing ancient proteins using matrix-assisted laser desorption ionization mass spectrometry, GEOCH COS A, 64(6), 2000, pp. 1043-1050
Citations number
63
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
GEOCHIMICA ET COSMOCHIMICA ACTA
ISSN journal
0016-7037 → ACNP
Volume
64
Issue
6
Year of publication
2000
Pages
1043 - 1050
Database
ISI
SICI code
0016-7037(200003)64:6<1043:NSFCAP>2.0.ZU;2-D
Abstract
Structural characterization of ancient proteins is confounded by the small quantity of material remaining in fossils, difficulties in purification, an d the inability to obtain sequence information by classical Edman degradati on. We present a microbore reversed phase high performance liquid chromatog raphy (rpHPLC) method for partial purification of small quantities (picomol es) of the bone protein osteocalcin (OC) and subsequent characterization of this material by matrix-assisted laser desorption ionization mass spectrom etry (MALDI-MS). The presence of OC in the modern and ancient samples was s uggested by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS- PAGE) and radioimmunoassay (RIA). The SDS-PAGE of material isolated from 80 0 yr BP and 10,000 yr BP bones demonstrates a band consistent with the mole cular weight of OC and the RIA indicated OC in concentrations of 0.2 to 450 ng/mg of bone for samples between 800 and 53,000 yr BP. In modern samples, we demonstrate the use of MALDI-MS to confirm the molecular weight of intac t OC and to sequence OC via peptide mass mapping and a novel derivatization approach with post-source decay analysis. MALDI-MS data for three ancient samples with RIA-confirmed osteocalcin (800 yr BP, 10,000 yr BP and 53,000 yr BP) indicate peaks with a molecular mass within the range of modern OC. Copyright (C) 2000 Elsevier Science Ltd.