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Analysis of the interferences in quantitation of a site-specifically PEGylated exendin-4 analog by the Bradford method.
Anal Biochem · 2014
Last updated 2026-05-28A study found that adding a large molecule called PEG to a diabetes drug (Ex4C) made it harder to measure the drug’s concentration using a common lab test. The test showed lower results because PEG blocked the dye from binding to certain parts of the drug, and longer PEG chains caused more interference.
AI summary of the abstract below.
| Journal | Anal Biochem, 2014 |
|---|---|
| Citations | 16 |
| Relative citation ratio | 0.54 |
| NIH percentile | 31 |
| Molecules | — |
Abstract
Protein modification has been found to affect the estimation of protein concentration in some of the traditional dye-based absorbance measurements. In this work, a distinct reduction in A595 was observed during the quantitation of a PEGylated exendin-4 analogue (Ex4C) by the Bradford method and the PEGylation process was found to interfere with the measurement. Lys(12), Arg(20), and Lys(27) were further proved to be the major amino acids that functioned as dye-binding sites. The shielding effect produced by the large polymer was demonstrated to depend on the length of PEG that was used for modification.
Verbatim abstract via PubMed 24953009 ↗