Epitope-Specific Response of Human Milk Immunoglobulins in COVID-19 Recovered Women.

The breastfeeding of infants by mothers who are infected with SARS-CoV-2 has become a dramatic healthcare problem. The WHO recommends that infected women should not abandon breastfeeding; however, there is still the risk of contact transmission. Convalescent donor milk may provide a defense against the aforementioned issue and can eliminate the consequences of artificial feeding.

Multiscale computation delivers organophosphorus reactivity and stereoselectivity to immunoglobulin scavengers.

Quantum mechanics/molecular mechanics (QM/MM) maturation of an immunoglobulin (Ig) powered by supercomputation delivers novel functionality to this catalytic template and facilitates artificial evolution of biocatalysts. We here employ density functional theory-based (DFT-b) tight binding and funnel metadynamics to advance our earlier QM/MM maturation of A17 Ig-paraoxonase (WTIgP) as a reactibody for organophosphorus toxins. It enables regulation of biocatalytic activity for tyrosine nucleophilic attack on phosphorus.

Microfluidic droplet platform for ultrahigh-throughput single-cell screening of biodiversity.

Ultrahigh-throughput screening (uHTS) techniques can identify unique functionality from millions of variants. To mimic the natural selection mechanisms that occur by compartmentalization in vivo, we developed a technique based on single-cell encapsulation in droplets of a monodisperse microfluidic double water-in-oil-in-water emulsion (MDE). Biocompatible MDE enables in-droplet cultivation of different living species.

Multiple sclerosis autoantigen myelin basic protein escapes control by ubiquitination during proteasomal degradation.

The vast majority of cellular proteins are degraded by the 26S proteasome after their ubiquitination. Here, we report that the major component of the myelin multilayered membrane sheath, myelin basic protein (MBP), is hydrolyzed by the 26S proteasome in a ubiquitin-independent manner both in vitro and in mammalian cells. As a proteasomal substrate, MBP reveals a distinct and physiologically relevant concentration range for ubiquitin-independent proteolysis.

Role of κ→λ light-chain constant-domain switch in the structure and functionality of A17 reactibody.

The engineering of catalytic function in antibodies requires precise information on their structure. Here, results are presented that show how the antibody domain structure affects its functionality. The previously designed organophosphate-metabolizing reactibody A17 has been re-engineered by replacing its constant κ light chain by the λ chain (A17λ), and the X-ray structure of A17λ has been determined at 1.

Heavy-light chain interrelations of MS-associated immunoglobulins probed by deep sequencing and rational variation.

The mechanisms triggering most of autoimmune diseases are still obscure. Autoreactive B cells play a crucial role in the development of such pathologies and, in particular, production of autoantibodies of different specificities. The combination of deep-sequencing technology with functional studies of antibodies selected from highly representative immunoglobulin combinatorial libraries may provide unique information on specific features in the repertoires of autoreactive B cells.

Heterogeneous catalysis on the phage surface: Display of active human enteropeptidase.

Enteropeptidase (EC 3.4.21.

RNA-hydrolyzing activity of human serum albumin and its recombinant analogue.

The comparative analysis of RNA-hydrolyzing activity of albumin from human serum and albumin expressed in methylotrophic yeast Pichia pastoris has been carried out. The rate of polyribonucleotide phosphodiester bond cleavage in the presence of recombinant albumin has been found to be similar to that of the reaction mediated by the native protein. According to 31P NMR data, RNA hydrolysis follows the mechanism of intermolecular trans-esterification to yield 2',3'-cyclophosphodiester reaction products that are further slowly hydrolyzed to form nucleoside-3'- and nucleoside-2'-phosphates.