2-Pyridine Carboxaldehyde for Semi-Automated Soft Spot Identification in Cyclic Peptides
Cyclic peptides are an attractive option as therapeutics due to their ability to disrupt crucial protein–protein interactions and their flexibility in display type screening strategies, but they come with their own bioanalytical challenges in metabolite identification. Initial amide hydrolysis of a...
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MDPI AG
2022-04-01
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Series: | International Journal of Molecular Sciences |
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Online Access: | https://www.mdpi.com/1422-0067/23/8/4269 |
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author | Haiying Zhang Silvi Chacko Joe R. Cannon |
author_facet | Haiying Zhang Silvi Chacko Joe R. Cannon |
author_sort | Haiying Zhang |
collection | DOAJ |
description | Cyclic peptides are an attractive option as therapeutics due to their ability to disrupt crucial protein–protein interactions and their flexibility in display type screening strategies, but they come with their own bioanalytical challenges in metabolite identification. Initial amide hydrolysis of a cyclic peptide results in a ring opening event in which the sequence is linearized. Unfortunately, the mass of the singly hydrolyzed sequence is the same (M + 18.0106 Da) irrespective of the initial site of hydrolysis, or soft spot. Soft spot identification at this point typically requires time-consuming manual interpretation of the tandem mass spectra, resulting in a substantial bottleneck in the hit to lead process. To overcome this, derivatization using 2-pyridine carboxaldehyde, which shows high selectivity for the alpha amine on the N-terminus, was employed. This strategy results in moderate- to high-efficiency derivatization with a unique mass tag and diagnostic ions that serve to highlight the first amino acid in the newly linearized peptide. The derivatization method and analytical strategy are demonstrated on a whole cell lysate digest, and the soft spot identification strategy is shown with two commercially available cyclic peptides: JB1 and somatostatin. Effective utilization of the automated sample preparation and interpretation of the resulting spectra shown here will serve to reduce the hit-to-lead time for generating promising proteolytically stable peptide candidates. |
first_indexed | 2024-03-09T13:33:19Z |
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institution | Directory Open Access Journal |
issn | 1661-6596 1422-0067 |
language | English |
last_indexed | 2024-03-09T13:33:19Z |
publishDate | 2022-04-01 |
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series | International Journal of Molecular Sciences |
spelling | doaj.art-92ea11a5cf6643c996ebfe08257c0b202023-11-30T21:15:21ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672022-04-01238426910.3390/ijms230842692-Pyridine Carboxaldehyde for Semi-Automated Soft Spot Identification in Cyclic PeptidesHaiying Zhang0Silvi Chacko1Joe R. Cannon2Department of Metabolism and Pharmacokinetics, Bristol-Myers Squibb Company, Princeton, NJ 08648, USADepartment of Metabolism and Pharmacokinetics, Bristol-Myers Squibb Company, Princeton, NJ 08648, USADepartment of Metabolism and Pharmacokinetics, Bristol-Myers Squibb Company, Princeton, NJ 08648, USACyclic peptides are an attractive option as therapeutics due to their ability to disrupt crucial protein–protein interactions and their flexibility in display type screening strategies, but they come with their own bioanalytical challenges in metabolite identification. Initial amide hydrolysis of a cyclic peptide results in a ring opening event in which the sequence is linearized. Unfortunately, the mass of the singly hydrolyzed sequence is the same (M + 18.0106 Da) irrespective of the initial site of hydrolysis, or soft spot. Soft spot identification at this point typically requires time-consuming manual interpretation of the tandem mass spectra, resulting in a substantial bottleneck in the hit to lead process. To overcome this, derivatization using 2-pyridine carboxaldehyde, which shows high selectivity for the alpha amine on the N-terminus, was employed. This strategy results in moderate- to high-efficiency derivatization with a unique mass tag and diagnostic ions that serve to highlight the first amino acid in the newly linearized peptide. The derivatization method and analytical strategy are demonstrated on a whole cell lysate digest, and the soft spot identification strategy is shown with two commercially available cyclic peptides: JB1 and somatostatin. Effective utilization of the automated sample preparation and interpretation of the resulting spectra shown here will serve to reduce the hit-to-lead time for generating promising proteolytically stable peptide candidates.https://www.mdpi.com/1422-0067/23/8/4269peptidemacrocyclic peptideproteolysisproteolytic stabilitysoft spotsite-specific conjugation |
spellingShingle | Haiying Zhang Silvi Chacko Joe R. Cannon 2-Pyridine Carboxaldehyde for Semi-Automated Soft Spot Identification in Cyclic Peptides International Journal of Molecular Sciences peptide macrocyclic peptide proteolysis proteolytic stability soft spot site-specific conjugation |
title | 2-Pyridine Carboxaldehyde for Semi-Automated Soft Spot Identification in Cyclic Peptides |
title_full | 2-Pyridine Carboxaldehyde for Semi-Automated Soft Spot Identification in Cyclic Peptides |
title_fullStr | 2-Pyridine Carboxaldehyde for Semi-Automated Soft Spot Identification in Cyclic Peptides |
title_full_unstemmed | 2-Pyridine Carboxaldehyde for Semi-Automated Soft Spot Identification in Cyclic Peptides |
title_short | 2-Pyridine Carboxaldehyde for Semi-Automated Soft Spot Identification in Cyclic Peptides |
title_sort | 2 pyridine carboxaldehyde for semi automated soft spot identification in cyclic peptides |
topic | peptide macrocyclic peptide proteolysis proteolytic stability soft spot site-specific conjugation |
url | https://www.mdpi.com/1422-0067/23/8/4269 |
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