ISSN:
1573-904X
Keywords:
epidermal growth factor
;
degradation kinetics
;
reversed-phase/ion-pair HPLC
;
amino acid sequencing
;
isoelectric focusing
;
electrospray ionization mass spectrometry
;
oxidation
;
deamidation
;
succinimide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Human epidermal growth factor 1-48 (hEGF 1-48, Des(49-53)hEGF) is a single chain polypeptide (48 amino acids; 3 disulfide bonds; 5445 Da) possessing a broad spectrum of biologic activity including the stimulation of cell proliferation and tissue growth. In this study, three primary aqueous degradation products of hEGF 1-48 were isolated using isocratic, reverse phase/ion-pair HPLC. The degradation products were characterized using amino acid sequencing, electrospray ionization mass spectrometry, isoelectric focusing, and degradation kinetics. Results indicate that hEGF 1-48 degrades via oxidation (Met21), deamidation (Asn1), and succinimide formation (Asp11). The relative contribution of each degradation pathway to the overall stability of hEGF 1-48 changes as a function of solution pH and storage condition. Succinimide formation at Asp11 is favored at pH 〈 6 in which aspartic acid is present mostly in its protonated form. Deamidation of Asn1 is favored at pH 〉 6. The relative contribution of Met21 oxidation is increased with decreasing temperature, storage as a frozen solution (−20°C), and exposure to fluorescent light.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1018903014204
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