Title
Thermal sensitivity as a quality control attribute for biotherapeutics: The L‐asparaginase case
Author
Han Yao, Evelien Wynendaele, Bart De Spiegeleer
Year
2019
Journal
Drug Testing and Analysis
Abstract
Thermal sensitivity, as a practical measure of thermostability, is an interesting quality attribute that can be used in the quality control (QC) release of biopharmaceuticals. This article investigates circular dichroism (CD) spectroscopy and nano‐differential scanning fluorimetry (nano‐DSF) to evaluate the thermal stability of E.coli L‐asparaginase (L‐ASNase) for QC purposes. In CD, molar ellipticity as a function of temperature (from 20 to 80°C) was measured at 222 nm. Different L‐ASNase samples dissolved in different diluents were investigated by determining the melting temperature (Tm) from the first derivative curve as well as the slope of the fitted sigmoidal function of the temperature gradient CD data. The obtained Tm values could be correlated with the L‐ASNase sample origin as well as with the pH of the diluent. The Tm values obtained from the CD data were moreover consistent with the Tm values determined by nano‐DSF, confirming their reliability. Next to the Tm value, also the slope of the fitted sigmoidal CD‐function was able to differentiate different L‐ASNase samples, including unstressed from stressed protein. By using both the Tm and the curve slope, the thermal stability of L‐ASNase was investigated, demonstrating and recommending the use of this heat‐stress characteristic as a QC quality attribute of proteins, which can be applied to detect substandard and falsified proteins.
Instrument
J-815
Keywords
Circular dichroism, Protein folding, Thermal stability, Secondary structure, Chemical stability, Thermodynamics, Pharmaceutical, Biochemistry