1
|
Jiang Y, Zhang X, Nie H, Fan J, Di S, Fu H, Zhang X, Wang L, Tang C. Dissecting diazirine photo-reaction mechanism for protein residue-specific cross-linking and distance mapping. Nat Commun 2024; 15:6060. [PMID: 39025860 PMCID: PMC11258254 DOI: 10.1038/s41467-024-50315-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 07/08/2024] [Indexed: 07/20/2024] Open
Abstract
While photo-cross-linking (PXL) with alkyl diazirines can provide stringent distance restraints and offer insights into protein structures, unambiguous identification of cross-linked residues hinders data interpretation to the same level that has been achieved with chemical cross-linking (CXL). We address this challenge by developing an in-line system with systematic modulation of light intensity and irradiation time, which allows for a quantitative evaluation of diazirine photolysis and photo-reaction mechanism. Our results reveal a two-step pathway with mainly sequential generation of diazo and carbene intermediates. Diazo intermediate preferentially targets buried polar residues, many of which are inaccessible with known CXL probes for their limited reactivity. Moreover, we demonstrate that tuning light intensity and duration enhances selectivity towards polar residues by biasing diazo-mediated cross-linking reactions over carbene ones. This mechanistic dissection unlocks the full potential of PXL, paving the way for accurate distance mapping against protein structures and ultimately, unveiling protein dynamic behaviors.
Collapse
Affiliation(s)
- Yida Jiang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Xinghe Zhang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Honggang Nie
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Jianxiong Fan
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Shuangshuang Di
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Hui Fu
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Xiu Zhang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Lijuan Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Chun Tang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
- Center for Quantitative Biology, PKU-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
| |
Collapse
|
2
|
Chen Y, Mutukuri TT, Wilson NE, Zhou QT. Pharmaceutical protein solids: Drying technology, solid-state characterization and stability. Adv Drug Deliv Rev 2021; 172:211-233. [PMID: 33705880 PMCID: PMC8107147 DOI: 10.1016/j.addr.2021.02.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/18/2021] [Accepted: 02/22/2021] [Indexed: 01/30/2023]
Abstract
Despite the boom in biologics over the past decade, the intrinsic instability of these large molecules poses significant challenges to formulation development. Almost half of all pharmaceutical protein products are formulated in the solid form to preserve protein native structure and extend product shelf-life. In this review, both traditional and emerging drying techniques for producing protein solids will be discussed. During the drying process, various stresses can impact the stability of protein solids. However, understanding the impact of stress on protein product quality can be challenging due to the lack of reliable characterization techniques for biological solids. Both conventional and advanced characterization techniques are discussed including differential scanning calorimetry (DSC), solid-state Fourier transform infrared spectrometry (ssFTIR), solid-state fluorescence spectrometry, solid-state hydrogen deuterium exchange (ssHDX), solid-state nuclear magnetic resonance (ssNMR) and solid-state photolytic labeling (ssPL). Advanced characterization tools may offer mechanistic investigations into local structural changes and interactions at higher resolutions. The continuous exploration of new drying techniques, as well as a better understanding of the effects caused by different drying techniques in solid state, would advance the formulation development of biological products with superior quality.
Collapse
Affiliation(s)
- Yuan Chen
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Tarun Tejasvi Mutukuri
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Nathan E Wilson
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - Qi Tony Zhou
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, USA.
| |
Collapse
|
3
|
Angelone D, Hammer AJS, Rohrbach S, Krambeck S, Granda JM, Wolf J, Zalesskiy S, Chisholm G, Cronin L. Convergence of multiple synthetic paradigms in a universally programmable chemical synthesis machine. Nat Chem 2021; 13:63-69. [PMID: 33353971 DOI: 10.1038/s41557-020-00596-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 10/29/2020] [Indexed: 11/08/2022]
Abstract
Although the automatic synthesis of molecules has been established, each reaction class uses bespoke hardware. This means that the connection of multi-step syntheses in a single machine to run many different protocols and reactions is not possible, as manual intervention is required. Here we show how the Chemputer synthesis robot can be programmed to perform many different reactions, including solid-phase peptide synthesis, iterative cross-coupling and accessing reactive, unstable diazirines in a single, unified system with high yields and purity. Developing universal and modular hardware that can be automated using one software system makes a wide variety of batch chemistry accessible. This is shown by our system, which performed around 8,500 operations while reusing only 22 distinct steps in 10 unique modules, with the code able to access 17 different reactions. We also demonstrate a complex convergent robotic synthesis of a peptide reacted with a diazirine-a process requiring 12 synthetic steps.
Collapse
Affiliation(s)
- Davide Angelone
- School of Chemistry, University of Glasgow, University Avenue, Glasgow, UK
| | | | - Simon Rohrbach
- School of Chemistry, University of Glasgow, University Avenue, Glasgow, UK
| | - Stefanie Krambeck
- School of Chemistry, University of Glasgow, University Avenue, Glasgow, UK
| | - Jarosław M Granda
- School of Chemistry, University of Glasgow, University Avenue, Glasgow, UK
| | - Jakob Wolf
- School of Chemistry, University of Glasgow, University Avenue, Glasgow, UK
| | - Sergey Zalesskiy
- School of Chemistry, University of Glasgow, University Avenue, Glasgow, UK
| | - Greig Chisholm
- School of Chemistry, University of Glasgow, University Avenue, Glasgow, UK
| | - Leroy Cronin
- School of Chemistry, University of Glasgow, University Avenue, Glasgow, UK.
| |
Collapse
|
4
|
Congdon MD, Gildersleeve JC. Enhanced Binding and Reduced Immunogenicity of Glycoconjugates Prepared via Solid-State Photoactivation of Aliphatic Diazirine Carbohydrates. Bioconjug Chem 2020; 32:133-142. [PMID: 33325683 DOI: 10.1021/acs.bioconjchem.0c00555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biological conjugation is an important tool employed for many basic research and clinical applications. While useful, common methods of biological conjugation suffer from a variety of limitations, such as (a) requiring the presence of specific surface-exposed residues, such as lysines or cysteines, (b) reducing protein activity, and/or (c) reducing protein stability and solubility. Use of photoreactive moieties including diazirines, azides, and benzophenones provide an alternative, mild approach to conjugation. Upon irradiation with UV and visible light, these functionalities generate highly reactive carbenes, nitrenes, and radical intermediates. Many of these will couple to proteins in a non-amino-acid-specific manner. The main hurdle for photoactivated biological conjugation is very low yield. In this study, we developed a solid-state method to increase conjugation efficiency of diazirine-containing carbohydrates to proteins. Using this methodology, we produced multivalent carbohydrate-protein conjugates with unaltered protein charge and secondary structure. Compared to carbohydrate conjugates prepared with amide linkages to lysine residues using standard NHS conjugation, the photoreactive prepared conjugates displayed up to 100-fold improved binding to lectins and diminished immunogenicity in mice. These results indicate that photoreactive bioconjugation could be especially useful for in vivo applications, such as lectin targeting, where high binding affinity and low immunogenicity are desired.
Collapse
Affiliation(s)
- Molly D Congdon
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Jeffrey C Gildersleeve
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| |
Collapse
|
5
|
A Novel Photoreactive Excipient to Probe Peptide-Matrix Interactions in Lyophilized Solids. J Pharm Sci 2019; 109:709-718. [PMID: 31034909 DOI: 10.1016/j.xphs.2019.04.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 04/13/2019] [Accepted: 04/19/2019] [Indexed: 11/22/2022]
Abstract
Excipients used in lyophilized protein drug products are often selected by a trial-and-error method, in part, because the analytical methods used to detect protein-excipient interactions in lyophilized solids are limited. In this study, photolytic labeling was used to probe interactions between salmon calcitonin (sCT) and excipients in lyophilized solids. Two diazirine-derived photo-excipients, photo-leucine (pLeu) and photo-glucosamine (pGlcN), were incorporated into lyophilized solids containing sCT, together with an unlabeled excipient (sucrose or histidine) at prelyophilization pH values from 6 to 9.9. Commercially available pLeu was selected as an ionizable photo-excipient and amino acid analog, while pGlcN was synthesized as an analog of sugar-based excipients. Photolytic labeling was induced by exposing the solids to UV light (365 nm, 30-60 min), and the resulting products were identified and quantified with liquid-chromatography mass spectrometry. The distribution of photo-reaction products was affected by the photoreactive reagent used, the type of unlabeled excipient, and the solution pH before lyophilization. When other components of the solid were identical, the extent and sites of labeling on sCT were different for pGlcN and pLeu. The results suggest that ionizable and nonionizable excipients interact differently with sCT in lyophilized solids and that photo-excipients can be used to map these interactions.
Collapse
|
6
|
Chen Y, Topp EM. Photolytic Labeling To Quantify Peptide-Water Interactions in Lyophilized Solids. Mol Pharm 2019; 16:1053-1064. [PMID: 30721080 DOI: 10.1021/acs.molpharmaceut.8b01031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interactions of a lyophilized peptide with water and excipients in a solid matrix were explored using photolytic labeling. A model peptide "KLQ" (Ac-QELHKLQ-NHCH3) was covalently labeled with NHS-diazirine (succinimidyl 4,4'-azipentanoate), and the labeled peptide (KLQ-SDA) was formulated and exposed to UV light in both solution and lyophilized solids. Solid samples contained the following excipients at a 1:400 molar ratio: sucrose, trehalose, mannitol, histidine, or arginine. Prior to UV exposure, the lyophilized solids were exposed to various relative humidity (RH) environments (8, 13, 33, 45, and 78%), and the resulting solid moisture content (Karl Fischer titration) and glass transition temperature ( Tg; differential scanning calorimetry, DSC) were measured. To initiate photolytic labeling, solution and solid samples were exposed to UV light at 365 nm for 30 min. Photolytic-labeling products were quantified using reversed-phase high-performance liquid chromatography (rp-HPLC) and mass spectrometry (MS). In lyophilized solids, studies excluding oxygen and using H218O confirmed that the source of oxygen in KLQ adducts with a mass increase of 18 amu are attributable to reaction with water, while those with a mass increase of 16 amu are not attributable to reaction with either water or molecular oxygen. In solids containing sucrose or trehalose, peptide-excipient adducts decreased with increasing solid moisture content, while peptide-water adducts increased only at lower RH exposure and then plateaued, in partial agreement with the water replacement hypothesis.
Collapse
Affiliation(s)
- Yuan Chen
- Department of Industrial and Physical Pharmacy, College of Pharmacy , Purdue University , 575 Stadium Mall Drive , West Lafayette , Indiana 47906 , United States
| | - Elizabeth M Topp
- Department of Industrial and Physical Pharmacy, College of Pharmacy , Purdue University , 575 Stadium Mall Drive , West Lafayette , Indiana 47906 , United States
| |
Collapse
|
7
|
Chen Y, Topp EM. Photolytic Labeling and Its Applications in Protein Drug Discovery and Development. J Pharm Sci 2018; 108:791-797. [PMID: 30339867 DOI: 10.1016/j.xphs.2018.10.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/09/2018] [Accepted: 10/10/2018] [Indexed: 11/19/2022]
Abstract
In this mini-review, the major types of photolytic labeling reagents are presented together with their reaction mechanisms. The applications of photolytic labeling in protein drug discovery and development are then discussed; these have expanded from studies of protein-protein interactions in vivo to protein-matrix interactions in lyophilized solids. The mini-review concludes with recommendations for further development of the approach, which include the need for new and more chemically diverse photo-reactive reagents and better understanding of the mechanisms of photolytic labeling reactions in various media.
Collapse
Affiliation(s)
- Yuan Chen
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907
| | - Elizabeth M Topp
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907.
| |
Collapse
|
8
|
Chen Y, Topp EM. Quantitative Analysis of Peptide-Matrix Interactions in Lyophilized Solids Using Photolytic Labeling. Mol Pharm 2018; 15:2797-2806. [PMID: 29792715 DOI: 10.1021/acs.molpharmaceut.8b00283] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Peptide-matrix interactions in lyophilized solids were explored using photolytic labeling with reversed phase high performance liquid chromatography (rp-HPLC) and mass spectrometric (MS) analysis. A model peptide (Ac-QELHKLQ-NHCH3) derived from salmon calcitonin was first labeled with a heterobifunctional cross-linker NHS-diazirine (succinimidyl 4,4'-azipentanoate; SDA) at Lys5 in solution, with ∼100% conversion. The SDA labeled peptide was then formulated with the following excipients at a 1:400 molar ratio and lyophilized: sucrose, trehalose, mannitol, histidine, arginine, urea, and NaCl. The lyophilized samples and corresponding solution controls were exposed to UV at 365 nm to induce photolytic labeling, and the products were identified by MS and quantified with rp-HPLC or MS. Peptide-excipient adducts were detected in the lyophilized solids except the NaCl formulation. With the exception of the histidine formulation, peptide-excipient adducts were not detected in solution and the fractional conversion to peptide-water adducts in solution was significantly greater than in lyophilized solids, as expected. In lyophilized solids, the fractional conversion to peptide-water adducts was poorly correlated with bulk moisture content, suggesting that the local water content near the labeled lysine residue differs from the measured bulk average. In lyophilized solids, the fractional conversion to peptide-excipient adducts was assessed using MS extracted ion chromatograms (EIC); subject to the assumption of equal ionization efficiencies, the fractional conversion to excipient adducts varied with excipient type. The results demonstrate that the local environment near the lysine residue of the peptide in the lyophilized solids can be quantitatively probed with a photolytic labeling method.
Collapse
Affiliation(s)
- Yuan Chen
- Department of Industrial and Physical Pharmacy College of Pharmacy , Purdue University , 575 Stadium Mall Drive , West Lafayette , Indiana 47906 , United States
| | - Elizabeth M Topp
- Department of Industrial and Physical Pharmacy College of Pharmacy , Purdue University , 575 Stadium Mall Drive , West Lafayette , Indiana 47906 , United States
| |
Collapse
|