Abstract
Peptide mapping and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) were conducted to characterize the human genome-based recombinant proteins. Accurate mass values for the deleted forms of the myeloid progenitor inhibitory factor chemokine (MPIF-1d23), and the keratinocyte growth factor (KGF-2d33) were measured as 8848.55 ± 0.25 and 16,175.87 ± 0.89 Da, respectively. The mass accuracy of delayed ion extraction MALDI-MS measurements was within 20 ppm of the cDNA predicted value. Reduction and alkylation of the chemokine showed the presence of six cysteine residues and three disulfide bonds. Additional confirmation of disulfide bonding among the cysteine residues of the chemokine was demonstrated by identifying the RP-HPLC separated tryptic and endoprotease Glu-C peptides. Three methionine residues of the chemokine were identified by MALDI-MS of its cyanogen bromide (CNBr) cleavage products. The KGF-2d33 growth factor, however, lacked the disulfide bonding between the two-cysteine residues and contained two free sulfhydryl groups. Direct analysis of the growth factor CNBr digest showed 7542.99, 4993.4, and 3107.7 Da peptides, which identified the methionine residues. Peptide mapping mass spectrometry indicated that host-specific posttranslational modifications had not influenced the gene expression work.
Submitted Version (
Free)
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
