Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance Spectroscopy
Glucagon, a 29-amino acid polypeptide hormone, is an essential therapeutic agent used in the emergency treatment of hypoglycemia. However, glucagon is inherently unstable in aqueous solution. While glucagon equilibrates between unordered and the secondary α-helix state in solution, it can quickly tr...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-11-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/27/22/7805 |
| _version_ | 1827644051393871872 |
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| author | Zhongli Bao Ya-Chi Cheng Justin Jun Wei Mary Ziping Luo Jack Yongfeng Zhang |
| author_facet | Zhongli Bao Ya-Chi Cheng Justin Jun Wei Mary Ziping Luo Jack Yongfeng Zhang |
| author_sort | Zhongli Bao |
| collection | DOAJ |
| description | Glucagon, a 29-amino acid polypeptide hormone, is an essential therapeutic agent used in the emergency treatment of hypoglycemia. However, glucagon is inherently unstable in aqueous solution. While glucagon equilibrates between unordered and the secondary α-helix state in solution, it can quickly transform into a different secondary β-sheet-rich amyloid-like fibril/oligomer structure under various conditions. Since changes in the secondary structure of glucagon can cause significant impacts, structure analysis is necessary and essential to assess the safety of the product. This study analyzed the secondary structure of glucagon products at the release and at the expiry using circular dichroism spectroscopy (CD) and 2D Nuclear Overhauser effect spectroscopy (2D NOESY). In order to also determine if structural differences exist between glucagon produced through different manufacturing processes, synthetic and recombinant glucagon products were used and compared. The CD results indicated that for all release and expired glucagon products, the structure compositions were 14 to 16% α-helix, 17 to 19% β-strand, 14 to 15% Turn, and 53 to 54% Unordered. This was consistent with the 2D NOESY analysis which showed that both products had an approximate α-helix composition of 14 to 17%. Overall, there were no significant differences in terms of the secondary structure between synthetic and recombinant glucagon products both at the release and at the expiry. |
| first_indexed | 2024-03-09T18:07:42Z |
| format | Article |
| id | doaj.art-290c322889b140d680eae7dceac72e0e |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T18:07:42Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-290c322889b140d680eae7dceac72e0e2023-11-24T09:21:26ZengMDPI AGMolecules1420-30492022-11-012722780510.3390/molecules27227805Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance SpectroscopyZhongli Bao0Ya-Chi Cheng1Justin Jun Wei2Mary Ziping Luo3Jack Yongfeng Zhang4Amphastar Pharmaceuticals, Inc., Rancho Cucamonga, CA 91730, USAAmphastar Pharmaceuticals, Inc., Rancho Cucamonga, CA 91730, USAAmphastar Pharmaceuticals, Inc., Rancho Cucamonga, CA 91730, USAAmphastar Pharmaceuticals, Inc., Rancho Cucamonga, CA 91730, USAAmphastar Pharmaceuticals, Inc., Rancho Cucamonga, CA 91730, USAGlucagon, a 29-amino acid polypeptide hormone, is an essential therapeutic agent used in the emergency treatment of hypoglycemia. However, glucagon is inherently unstable in aqueous solution. While glucagon equilibrates between unordered and the secondary α-helix state in solution, it can quickly transform into a different secondary β-sheet-rich amyloid-like fibril/oligomer structure under various conditions. Since changes in the secondary structure of glucagon can cause significant impacts, structure analysis is necessary and essential to assess the safety of the product. This study analyzed the secondary structure of glucagon products at the release and at the expiry using circular dichroism spectroscopy (CD) and 2D Nuclear Overhauser effect spectroscopy (2D NOESY). In order to also determine if structural differences exist between glucagon produced through different manufacturing processes, synthetic and recombinant glucagon products were used and compared. The CD results indicated that for all release and expired glucagon products, the structure compositions were 14 to 16% α-helix, 17 to 19% β-strand, 14 to 15% Turn, and 53 to 54% Unordered. This was consistent with the 2D NOESY analysis which showed that both products had an approximate α-helix composition of 14 to 17%. Overall, there were no significant differences in terms of the secondary structure between synthetic and recombinant glucagon products both at the release and at the expiry.https://www.mdpi.com/1420-3049/27/22/7805glucagoncircular dichroismnuclear magnetic resonancespectroscopysynthetic peptideinjection |
| spellingShingle | Zhongli Bao Ya-Chi Cheng Justin Jun Wei Mary Ziping Luo Jack Yongfeng Zhang Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance Spectroscopy Molecules glucagon circular dichroism nuclear magnetic resonance spectroscopy synthetic peptide injection |
| title | Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance Spectroscopy |
| title_full | Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance Spectroscopy |
| title_fullStr | Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance Spectroscopy |
| title_full_unstemmed | Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance Spectroscopy |
| title_short | Secondary Structure Characterization of Glucagon Products by Circular Dichroism and Nuclear Magnetic Resonance Spectroscopy |
| title_sort | secondary structure characterization of glucagon products by circular dichroism and nuclear magnetic resonance spectroscopy |
| topic | glucagon circular dichroism nuclear magnetic resonance spectroscopy synthetic peptide injection |
| url | https://www.mdpi.com/1420-3049/27/22/7805 |
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