PEGylation prevents the N-terminal degradation of megakaryocyte growth and development factor.
OBJECTIVE
Determine the effect of PEGylation on in-vitro degradation for recombinant human Megakaryocyte Growth and Development Factor (rHuMGDF) in the neutral pH range.


METHODS
Degradation products were characterized by cation-exchange HPLC, N-terminal sequencing and mass spectrometry.


RESULTS
The main route of degradation was through non-enzymatic cyclization of the first two amino acids and subsequent cleavage to form a diketopiperazine and des(Ser, Pro)rHuMGDE This reaction was prevented by alkylation of the N-terminus by polyethylene glycol (PEG).


CONCLUSIONS
PEGylation of proteins is commonly performed to achieve increased in-vivo circulation half-lives. For rHuMGDF, an additional advantage of PEGylation was enhanced in-vitro shelf-life stability.
Guerra
P I
PI
Department of Pharmaceutics, Amgen Inc., Thousand Oaks, California 91320, USA.
Acklin
C
C
Kosky
A A
AA
Davis
J M
JM
Treuheit
M J
MJ
Brems
D N
DN
D000478:Alkylation; D000900:Anti-Bacterial Agents; D002851:Chromatography, High Pressure Liquid; D054659:Diketopiperazines; D004356:Drug Storage; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D010449:Peptide Mapping; D010879:Piperazines; D011092:Polyethylene Glycols / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D013696:Temperature; D013926:Thrombopoietin / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D054659:Diketopiperazines; D010446:Peptide Fragments; D010879:Piperazines; D011994:Recombinant Proteins; C103117:polyethylene glycol-recombinant human megakaryocyte growth and development factor; D011092:Polyethylene Glycols; D013926:Thrombopoietin