Temperature-Insensitive Near-Infrared Method for Determination of Protein Concentration during Protein Crystal Growth

Abstract

A temperature-insensitive method for measuring protein concentration in aqueous solutions using near-infrared spectroscopy is described. The method, which is based on identification of the net analyte signal of single-beam spectra, can be calibrated using a single protein absorbance measurement and is thus well suited for crystallization monitoring where the quantity of protein is limited. The method is applied to measurements of glucose-isomerase concentration in a sodium phosphate buffer that is actively varied over the temperature range of 4-24 degrees C. The standard error of prediction using the optimized spectral range of 4670-4595 cm(-1) is 0.12 mg/mL with no systematic trend in the residuals with solution temperature. The method is also applied to previously collected spectra of hen egg-white lysozyme and yields a standard error of prediction of 0.14 mg/mL. Spectra sampled at discrete wavelengths can also be used for calibration and prediction with performance comparable to that obtained with spectral bands. A set of four wavelengths are identified that can be used to predict concentrations of both proteins with a standard error less than 0.14 mg/mL.

Optimal seed recipe design for crystal size distribution control for batch cooling crystallisation processes

“…Crystallisation processes have a wide range of application as a separation technique in many chemical, petrochemical, food, pharmaceutical and microelectronics industries (Abbott, 2001;Mangin et al, 2006;Middlebrooks, 2001;Olesberg et al, 2000;Shi et al, 2005;Wiencek, 2002). Although crystallisation is often used when the end product is required in crystalline form (Braatz, 2002;Hounslow and Reynolds, 2006), the process development and scale-up is not straightforward.…”

Measurement of temperature and concentration dependences of refractive index of hen‐egg‐white lysozyme solution

“…However, for the purpose of protein crystal growth study, some in-situ monitoring techniques are more competitive. Raman spectroscopy was recently used for real-time monitoring of the hen-egg-white lysozyme (HEWL) concentration during crystallization [12]; more recently, NIR (near infrared) method was utilized to measure the protein concentration [13]. For more detailed concentration mapping, interferometry was proposed to be a more convenient tool by Shlichta [14] in 1980s.…”

Optimization of crystallization of biological macromolecules using dialysis combined with temperature control

“…Knowledge of the phase diagram is of key importance when designing and controlling a crystallization process (Astier & Veesler, 2008;Vekilov, 2012;Zhang et al, 2014). In the case of macromolecules such as proteins, the availability of accurate phase diagram data is limited owing to the diversity of their structures and the lack of suitable experimental setups to readily perform reliable measurements of protein solubility during crystallization using a small amount of protein sample (Garcia-Ruiz et al, 1999;Olesberg et al, 2000;Curtis et al, 2001;Asherie, 2004;Dumetz et al, 2007;Yin et al, 2008;Y. Zhang et al, 2012).…”