Biology subjects

Pompach, P.

Publications and source records attributed to Pompach, P..

3 recordsLinked to original sources

bioRxiv2024

A selective alternative pathway complement inhibitor for treatment of paroxysmal nocturnal hemoglobinuria

The complement system, a critical component of the human innate immune system, enhances the ability to clear microbes and damaged cells. Dysregulation of this system, particularly the alternative pathway (AP), can lead to several rare blood disorders such as paroxysmal nocturnal hemoglobinuria (PNH). This study introduces SH-01, a blood parasite-derived, novel recombinant protein which selectively inhibits the AP. We show that SH-01 effectively prevents the lysis of erythrocytes isolated from PNH patients. Unlike current treatments such as eculizumab, SH-01 targets the AP without impairing the classical or lectin pathways, reducing the risk of infections and extravascular hemolysis. SH-01 functions through a unique two-stage mechanism, preventing C3b deposition and inhibiting AP C5 convertase activity while maintaining the amplification loops functionality. Immunization studies in mice showed no significant immune response against SH-01, and the protein exhibited high stability and no acute toxicity. These findings suggest SH-01 as a promising candidate for treatment of PNH and other diseases characterized by AP hyperactivation, offering a more targeted therapeutic and thus safer approach.

immunology↗

bioRxiv2023

Structural Insights into the Interaction Between Adenovirus C5 Hexon and Human Lactoferrin

Adenovirus (AdV) infection of the respiratory epithelium is common, but poorly understood. Human AdV species C types, such as HAdV-C5, utilize the Coxsackie-adenovirus receptor (CAR) for attachment and subsequently integrins for entry. CAR and integrins are however located deep within the tight junctions in the mucosa where they would not be easily accessible. Recently, a model for CAR-independent AdV entry was proposed. In this model, human lactoferrin (hLF), an innate immune protein, aids the viral uptake into epithelial cells by mediating interactions between the major capsid protein, hexon, and yet unknown host cellular receptor(s). However, a detailed understanding of the molecular interactions driving this mechanism is lacking. Here, we present a new cryo-EM structure of HAdV-5C hexon at high resolution alongside a hybrid structure of HAdV-5C hexon complexed with human lactoferrin (hLF). These structures reveal the molecular determinants of the interaction between hLF and HAdV-C5 hexon. hLF engages hexon primarily via its N-terminal lactoferricin (Lfcin) region, interacting with hexons hypervariable region 1 (HVR-1). Mutational analyses pinpoint critical Lfcin contacts and also identify additional regions within hLF that critically contribute to hexon binding. Our study sheds more light on the intricate mechanism by which HAdV-C5 utilizes soluble hLF/Lfcin for cellular entry. These findings hold promise for advancing gene therapy applications and inform vaccine development.

biochemistry↗

bioRxiv2023

Development of a PNGase Rc column for online deglycosylation of complex glycoproteins during HDX-MS

Protein glycosylation is one of the most common PTMs and many cell surface receptors, extracellular proteins and biopharmaceuticals are glycosylated. However, HDX-MS analysis of such important glycoproteins has so far been limited by difficulties in determining the HDX of the protein segments that contain glycans. We have developed a column containing immobilized PNGase Rc (from Rudaea cellulosilytica) that can readily be implemented into a conventional HDX-MS setup to allow improved analysis of glycoproteins. We show that HDX-MS with the PNGase Rc column enables efficient online removal of N-linked glycans and the determination of the HDX of glycosylated regions in several complex glycoproteins. Additionally, we use the PNGase Rc column to perform a comprehensive HDX-MS mapping of the binding epitope of a mAb to c-Met, a complex glycoprotein drug target. Importantly, the column retains high activity in the presence of common quench-buffer additives like TCEP and urea and performed consistent across 114 days of extensive use. Overall, our work shows that HDX-MS with the integrated PNGase Rc column can enable fast and efficient online deglycosylation at harsh quench conditions to provide comprehensive analysis of complex glycoproteins.

biochemistry↗