Biology subjects

Kummer, N.

Publications and source records attributed to Kummer, N..

3 recordsLinked to original sources

bioRxiv2026

Fungal hydrophobins unleashed from food waste: production, rodlet assembly, and functional properties in Ganoderma adspersum

Ganoderma adspersum is a white-rot fungus (WRF) that produces amphipathic, surface-active proteins, known as hydrophobins. To explore sustainable routes for protein production and waste valorization, G. adspersum was cultivated under defined shaking conditions using different carbon and nitrogen sources, including apple skin food waste. From these cultures, we report for the first time the isolation and characterization of a novel class I hydrophobin, designated as Gad1. Atomic force microscopy revealed abundant rodlet-like nanostructures consistent with class I hydrophobin assemblies, and Raman spectroscopy confirmed {beta}-sheet enrichment typical of amyloid-like organization. MALDI-TOF mass spectrometry further identified Gad1 along with additional hydrophobin-like proteins in the foam. Hydrophobin-enriched foam extracts were used to form stable oil-in-water emulsions that could be converted into porous, freezedried composite aerogels. These findings expand the known diversity of hydrophobins in whiterot fungi and demonstrate that food-waste-derived substrates can support hydrophobin production and functional biomaterial formation.

biophysics↗

bioRxiv2025

Anti-amyloid antibody effects on Aβ-42 protein aggregates profiled using nanospectroscopy

Anti-amyloid beta (A{beta}) drugs such as aducanumab and lecanemab are designed to clear brain amyloids and slow Alzheimers disease (AD) progression. While immunoassays provide ensemble-level details on anti-A{beta} drug interactions with protein targets, their interfacial effects are largely unknown at a single-particle level. Here, we profile untreated and aducanumab-treated A{beta}-42 protein aggregates from oligomers to fibrils using atomic force microscopy coupled with infrared spectroscopy (nanospectroscopy). Based on the recorded morphological and secondary structure details of aducanumab-treated A{beta}-42 aggregates using nanospectroscopy, we observed a reduction in oligomer prevalence and formation of larger diameter fibril bundles compared to identically prepared untreated-A{beta}-42 peptides. Conversely, controls based on lecanemab did not reveal any quenching of the A{beta}-42 oligomer generation. Moreover, lecanemab was evidenced to bind along the full length of the A{beta}-42 protofibril surface preferentially. Importantly, the structure of A{beta}-42 fibrils did not disassemble in both studies upon the adsorption of aducanumab and lecanemab. Additional experiments were also conducted, such as aggregation kinetic assays and Fourier transform infrared spectroscopy on aducanumab and lecanemab-treated A{beta}-42 protein aggregates that corroborated the findings from nanospectroscopy studies. Our work highlights the usefulness of nanospectroscopy in studying elemental anti-amyloid antibody interactions with protein biomarkers, a requisite for improving Alzheimers disease-modifying treatments.

biophysics↗

bioRxiv2024

On Levodopa interactions with brain disease proteins at the nanoscale

The cerebral accumulation of -Synuclein (-Syn) and amyloid {beta}-1-42 (A{beta}-42) proteins are known to play a crucial role in the pathology of neurocognitive disorders such as Parkinsons disease (PD). Currently, Levodopa (L-dopa) is the dopamine replacement therapy for treating bradykinetic symptoms visible in PD patients. Here, we use atomic force microscopy to evidence at nanometer length scales the effects of L-dopa on the morphology of -Syn and A{beta}-42 protein fibrils. L-dopa treatment reduces the length and diameter of both types of protein fibrils, with a stark reduction observed for A{beta}-42 both in physiological buffer and human spinal fluid. The insights gained on A{beta}-42 fibril disassembly from the nanoscale imaging experiments are substantiated using atomic-scale molecular dynamics simulations. Our results reveal the mechanism governing L-dopa-driven reversal of protein aggregation, which may be useful in drug design of small molecule drugs for potentially treating neurocognitive disorders and provide leads for designing chemical effector-mediated disassembly of protein architectures.

neuroscience↗