Open AccessDesign and Study of PEG Linkers That Enable Robust Characterization of PEGylated Proteins
Author(s) -
Anumita Saha-Shah,
Shuchen Sun,
John Kong,
Wendy Zhong,
Benjamin F. Mann
Publication year - 2021
Publication title -
acs pharmacology and translational science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.271
H-Index - 10
ISSN - 2575-9108
DOI - 10.1021/acsptsci.1c00112
Subject(s) - pegylation , bioconjugation , peg ratio , linker , chemistry , peptide , combinatorial chemistry , amino acid , conjugate , biochemistry , characterization (materials science) , nanotechnology , polyethylene glycol , materials science , computer science , mathematical analysis , mathematics , finance , economics , operating system
Several PEGylated therapeutic proteins are approved drugs, and more are under development. However, the synthesis and characterization of these bioconjugates, especially heterogeneous mixtures of PEGylated proteins, are challenging. The present study focuses on the development of PEG linkers that can be installed through biocatalytic route and render much simpler and insightful analytical characterization of PEG-protein conjugates. This linker enables traditional peptide mapping assay to determine protein sequence coverage, natural PTMs, and PEG attachment sites. Novel PEG linkers are cleavable during traditional sample preparation, leaving behind reporter amino acids to allow the determination of PEG attachment sites by peptide mapping. Products of transglutaminase-catalyzed bioconjugation of 5K PEG to Interferon α-2b were analyzed, and K31, K134, and K164 were identified as the PEGylation sites; the former two being newly determined sites demonstrates the sensitivity of the approach. In another instance, conjugation sites on Interleukin-2-PEG conjugation were found to be K31, K47, K48, and K75.