Revealing the Dynamic Allosteric Changes Required for Formation of the Cysteine Synthase Complex by Hydrogen-Deuterium Exchange MS.

CysE and CysK, the last two enzymes of the cysteine biosynthetic pathway, engage in a bienzyme complex, cysteine synthase, with yet incompletely characterized three-dimensional structure and regulatory function. Being absent in mammals, the two enzymes and their complex are attractive targets for antibacterial drugs. We have used hydrogen/deuterium exchange MS to unveil how complex formation affects the conformational dynamics of CysK and CysE.

Discovery of Highly Active Recombinant PNGase H Variants Through the Rational Exploration of Unstudied Acidobacterial Genomes.

Peptide- -(-acetyl-β-glucosaminyl) asparagine amidases (PNGases, -glycanases, EC 3.5.1.

An intact C-terminal end of albumin is required for its long half-life in humans.

Albumin has an average plasma half-life of three weeks and is thus an attractive carrier to improve the pharmacokinetics of fused therapeutics. The half-life is regulated by FcRn, a cellular receptor that protects against intracellular degradation. To tailor-design the therapeutic use of albumin, it is crucial to understand how structural alterations in albumin affect FcRn binding and transport properties.

Circularized and solubility-enhanced MSPs facilitate simple and high-yield production of stable nanodiscs for studies of membrane proteins in solution.

Recently, an enzymatic reaction was utilized to covalently link the N and C termini of membrane scaffold proteins to produce circularized nanodiscs that were more homogeneous and stable than standard nanodiscs. We continue this development and aim for obtaining high yields of stable and monodisperse nanodiscs for structural studies of membrane proteins by solution small-angle scattering techniques. Based on the template MSP1E3D1, we designed an optimized membrane scaffold protein (His-lsMSP1E3D1) with a sortase recognition motif and high abundance of solubility-enhancing negative charges.

Unusual Self-Assembly of the Recombinant Chlamydia trachomatis Major Outer Membrane Protein-Based Fusion Antigen CTH522 Into Protein Nanoparticles.

Sexually transmitted Chlamydia trachomatis infects more than 100 million people annually, and untreated chlamydia infections can cause severe complications. Therefore, there is an urgent need for a chlamydia vaccine. The Ctrachomatis major outer membrane protein (MOMP) is highly immunogenic but is a challenging vaccine candidate by being an integral membrane protein, and the immunogenicity depends on a correctly folded structure.

A Two-pronged Binding Mechanism of IgG to the Neonatal Fc Receptor Controls Complex Stability and IgG Serum Half-life.

The success of recombinant monoclonal immunoglobulins (IgG) is rooted in their ability to target distinct antigens with high affinity combined with an extraordinarily long serum half-life, typically around 3 weeks. The pharmacokinetics of IgGs is intimately linked to the recycling mechanism of the neonatal Fc receptor (FcRn). For long serum half-life of therapeutic IgGs, the highly pH-dependent interaction with FcRn needs to be balanced to allow efficient FcRn binding and release at slightly acidic pH and physiological pH, respectively.