A nonchromatographic process for purification of secretory immunoglobulins from caprine whey

Abstract

Secretory immunoglobulins are an important antibody class being primarily responsible for immunoprotection of mucosal surfaces. A simple, non-chromatographic purification process for secretory immunoglobulins from caprine whey was developed. In the first process step whey was concentrated 30-40-fold on a 500 kDa membrane, thereby increasing the purity from 3% to 15%. The second step consisted of a fractionated PEG precipitation, in which high molecular weight impurities were removed first and in the second stage the secretory immunoglobulins were precipitated, leaving a majority of the low molecular weight proteins in solution. The re-dissolved secretory immunoglobulin fraction had a purity of 43% which could then be increased to 72% by diafiltration at a volume exchange factor of 10. Further increase of purity was only possible at the expense of very high buffer consumption. If diafiltration was performed directly after ultrafiltration, followed by precipitation, the yield was higher but purity was only 54%. Overall, filtration performance was characterized by high concentration polarization, therefore process conditions were set to low trans-membrane pressure and moderate protein concentration. As such purity and to a lesser extent throughput were the major objectives rather than yield, since whey, as a by-product of the dairy industry, is a cheap raw material of almost unlimited supply. Ultra-/diafiltration performance was described well by correlations using dimensionless numbers. Compared with a theoretical model (Graetz/Leveque solution) the flux was slightly overestimated. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:642-653, 2017.

Neutralising Effects of Different Antibodies on Clostridioides difficile Toxins TcdA and TcdB in a Translational Approach

“…The SC protects the sIgA complex from proteolytic cleavage and binds microbial antigens and certain receptors via specific glycan structures [ 18 ]. sIgA can be purified in sufficient amounts from milk or whey of animals such as goats and cows and could potentially be used for the prevention of certain GI disorders [ 19 , 20 , 21 ]. In particular, glycosylation patterns of caprine and human sIgA show a high similarity [ 22 ].…”

Fractal dimension of antibody‐PEG precipitate: Light microscopy for the reconstruction of 3D precipitate structures

“…Fractal dimensions of protein precipitates and agglomerates have been proposed to characterize their structure, but never derived from the 3D structure of the precipitate. PEG precipitation has been described for whey protein recovery and purification of antibodies , enzymes, and viruses . In almost all applications, the resulting structure of the precipitate itself has been ignored, partly due to the lack of readily available and simple methodology to assess it.…”