Biology subjects

Neuwirthova, T.

Publications and source records attributed to Neuwirthova, T..

3 recordsLinked to original sources

bioRxiv2026

Learning the structural diversity in random protein sequence space

The universe of possible protein sequences is astronomically large, yet our understanding of the sequence-structure relationship is confined to the infinitesimal fraction used currently by life. Determining whether "foldable" architectures are rare singularities or accessible solutions is critical for understanding protein evolution and designing novel proteins. Here, we map the structural landscape of random sequence space by screening one million synthetic proteins using a high-throughput in vivo FRET biosensor. We reveal that this space is structurally heterogeneous, populated not only by disordered chains and stress-inducing aggregates but also by "benign" compact structures that resemble globular proteins and evade cellular chaperone responses. By training machine learning models on these phenotypes, we show that structural potential is learnable and generalizes to natural proteomes. These findings demonstrate that biology-like folds are accessible from random sequences with surprising frequency, providing data required to expand generative protein design beyond evolutionary priors.

synthetic biology↗

bioRxiv2025

Ancient amino acid sets enable stable protein folds

Early proteins likely arose from a chemically limited set of amino acids available through prebiotic chemistry, raising a central question in molecular evolution: could such primitive compositions yield stable, functional folds? Using de novo design, we constructed three ancient protein architectures using a reduced, evolution-inspired alphabet of ten amino acids, e.g. lacking all basic and aromatic residues. The resulting structures adopted their intended topologies and showed exceptional resistance to thermal and chemical denaturation. Computational simulations further revealed that proteins built from this restricted alphabet were as mutation-resilient as those using all twenty canonical residues. Besides their evolutionary implications, our results provide a foundation for minimalist protein design and generation of simplified, robust systems in minimal cell engineering.

biochemistry↗

bioRxiv2021

Structured proteins are abundant in unevolved sequence space

Natural proteins represent numerous but tiny structure/function islands in a vast ocean of possible protein sequences, most of which has not been explored by either biological evolution or research. Recent studies have suggested this uncharted sequence space possesses surprisingly high structural propensity, but development of an understanding of this phenomenon has been awaiting a systematic high-throughput approach. Here, we designed, prepared, and characterized two combinatorial protein libraries consisting of randomized proteins, each 105 residues in length. The first library constructed proteins from the entire canonical alphabet of 20 amino acids. The second library used a subset of only 10 residues (A,S,D,G,L,I,P,T,E,V) that represent a consensus view of plausibly available amino acids through prebiotic chemistry. Our study shows that compact conformations resistant to proteolysis are (i) abundant (up to 40%) in random sequence space, (ii) independent of general Hsp70 chaperone system activity, and (iii) not granted solely by "late" and complex amino acid additions. The Hsp70 chaperone system effectively increases solubility and refoldability of the canonical alphabet but has only a minor impact on the "early" library. The early alphabet proteins are inherently more soluble and refoldable, possibly assisted by the cell-like environment in which these assays were performed. Our work indicates that both early and modern amino acids are predisposed to supporting protein structure (either in forms of oligomers or globular/molten globule structures) and that protein structure may not be a unique outcome of evolution.

synthetic biology↗