Measure previously undetectable structural changes in biomolecules with RedShiftBio AQS3pro

ATA Scientific Pty Ltd
Monday, 13 December, 2021


During biopharmaceutical manufacturing, proteins can undergo conformational changes that can alter their secondary structure and lead to aggregation, which ultimately affects their efficacy and specificity.

Proteins are complex, labile molecules that present considerable challenges during drug development. Conventional analytical techniques like Fourier-transform infrared (FTIR) spectroscopy and far-ultraviolet circular dichroism (far-UV CD) have considerable utility for measuring secondary structure but inherently possess several practical limitations. The need for high sensitivity, a wide dynamic range, a simplified and automated workflow, and high repeatability is significant and, until now, has not been adequately provided. The solution for today’s researcher is Microfluidic Modulation spectroscopy (MMS).

RedShiftBio’s AQS3pro, powered by MMS, exploits the inherent utility of IR spectroscopy to elucidate results for Aggregation, Quantitation, Stability, Similarity and Structure in a single analysis. Sensitivity is improved up to 30x that of conventional FTIR instrumentation with a desirable concentration range of 0.1 mg/mL to over 200 mg/mL with protein analytics that is equally enviable to the operator and the researcher. The time saving for sample testing can be more than 80% thanks to the fully automated multi-sample capability.

Often the buffers used in a formulation are not compatible for the analytical method, as seen with spectopolarimetry. The AQS3pro experiences no interference from excipients in the buffer. This is a game changer, to measure at concentration, and in the final drug conditions, removing the guesswork from formulation, de-risking many steps.

What is the magic behind the AQS3pro system?

There are 3 key components in the AQS3pro that separate it from all others: 1) A mid IR tuneable quantum cascade laser, 2) a thermal, electrically cooled detector, and 3) a Y-shaped microfluidic transmission cell.

The tuneable laser provides an optical signal almost 100x brighter than the conventional light source used in FTIR, allowing the use of a simple thermal electrically cooled detector without the need for liquid nitrogen cooling. Given the intensity of the laser, the system is amenable to low concentration samples as low 0.1 mg/mL. The sample and reference stream are injected alternately through the Y-shaped microfluidic cell passing through the observation zone. Alternating at a rate of 1–5 Hz, the absorbance of the reference and sample are measured almost simultaneously, allowing the reference absorbance to be subtracted from the sample absorbance in real time, resulting in the collection of reference corrected absorbance spectra. Real-time buffer subtraction and auto-referencing greatly enhances the sensitivity method and produces an almost drift-free signal. The speed of the AQS3pro impresses; where it may take 30 min per sample for the FTIR the MMS clocks in at 1.5 min. The AQS3delta analytics package is refreshingly simple and intuitive, applying advanced analytical tools enabling its use in a vast range of applications across the industry.

What does the AQS3pro actually measure?

This is an infrared system that measures the Amide 1 band of a protein, in the wavenumber range of about 1580–1720. Alternating between buffer and sample produces a differential absorbance plot which is interpolated into a spectrum and in turn converted to a second derivative affording fine detail changes from spectrum to spectrum to be elucidated. Flipping the spectra shows the baselines and area of overlap plot, enabling you to look at similarity and trends between spectra. This can then be deconvoluted using a normal Gaussian deconvolution, giving rise to secondary structure motifs, the percentage of the components such as α-Helix, β-Sheet, and Anti-parallel β-Sheet Higher Order Structures (HOS).

De-risk drug development

MMS’s sensitive, accurate measurements coupled with a robust data analysis package provide simple, accessible, and reliable results to de-risk and accelerate drug development workflows. The AQS3pro can identify at-risk candidates far earlier than traditional methods, clearly saving time and resources.

ATA Scientific are proud to have the RedShiftBio AQS3pro within our suite of instrumentation. Should you require further information or a demo, please contact us.

For more information: https://www.atascientific.com.au/products/redshiftbio-aqs3pro/.

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