Aqueous stability of human epidermal growth factor 1-48

• Published in: Pharmaceutical research 1994-12, Vol.11 (12), p.1712-1720
• Main Authors: SENDEROFF, R. I, WOOTTON, S. C, BOCTOR, A. M, TSUN MING CHEN, GIORDANI, A. B, JULIAN, T. N, RADEBAUGH, G. W
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Biological and medical sciences; Drug Stability; Epidermal Growth Factor - chemistry; Fluorescence; General and cellular metabolism. Vitamins; Hydrogen-Ion Concentration; Medical sciences; Molecular Sequence Data; Pharmacology. Drug treatments; Temperature
• ISSN: 0724-8741; 1573-904X
• DOI: 10.1023/A:1018903014204

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 degrees C), and exposure to fluorescent light.