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Updated: Mar 9, 2026
Surface Passivation for Single-molecule Protein Studies
Published on: April 24, 2014
Self-Assembly PEGylation Retaining Activity (SPRA) Technology via a Host-Guest Interaction Surpassing Conventional
Tatsunori Hirotsu1,2, Taishi Higashi1, Irhan Ibrahim Abu Hashim1,3
1Graduate School of Pharmaceutical Sciences, Kumamoto University , 5-1 Oe-honmachi, Chuo-ku, Kumamoto 862-0973, Japan.
Abstract:
Polyethylene glycol (PEG) modification (PEGylation) is one of the best approaches to improve the stabilities and blood half-lives of protein drugs; however, PEGylation dramatically reduces the bioactivities of protein drugs. Here, we present "self-assembly PEGylation retaining activity" (SPRA) technology via a host-guest interaction between PEGylated β-cyclodextrin (PEG-β-CyD) and adamantane-appended (Ad) proteins. PEG-β-CyD formed stable complexes with Ad-insulin and Ad-lysozyme to yield SPRA-insulin and SPRA-lysozyme, respectively. Both SPRA-proteins showed high stability against heat and trypsin digest, comparable with that of covalently PEGylated protein equivalents. Importantly, the SPRA-lysozyme possessed ca. 100% lytic activity, whereas the activity of the covalently PEGylated lysozyme was ca. 23%. Additionally, SPRA-insulin provided a prolonged and peakless blood glucose profile when compared with insulin glargine. It also showed no loss of activity. In contrast, the covalently PEGylated insulin showed a negligible hypoglycemic effect. These findings indicate that SPRA technology has potential as a generic method, surpassing conventional PEGylation methods for proteins.
