Immunoglobulins M Survive Low-pH Conditions Used for Virus Inactivation and for Elution from Bioaffinity Columns

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014

This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.

Hyperimmunised bovine milk and whey: influence of pH and enzymatic treatments on the antigen-binding capacity of immunoglobulin G

BACKGROUND

Hyperimmunised bovine milk and whey (whole and defatted) were submitted at 37°C to different pH values (between 1 and 10) and enzymes (pepsin, trypsin and chymotrypsin) at their optimum pH and the IgG immunoactivity against Campylobacter jejuni was measured by means of ELISA assays.

RESULTS

The kinetic antigen-binding capacity (ABC) losses follow a hyperbolic-type equation. The ABC of IgG is strongly reduced at low pH (1 and 2) and the effect is lower at alkaline pH (8 and 10). The presence of pepsin (at their optimum pH of 2) almost completely reduced the IgG ABC after 2 h of treatment. The ABCs are higher in whole products (milk and whey). The influence of trypsin and quimotrypsin on the ABCs is moderate (ABC losses lower that 25%).

CONCLUSIONS

The ABC of IgG obtained from hyperimmunised bovine defatted milk and whey is largely reduced in conditions similar to those found in the human digestive tract. Only whole milk can maintain around 40% of their initial ABC. IgG encapsulation or other methods to protect the immunoglobulin activities could be an alternative to use these type of products in final foods formulae.