Researchers Identify D-Retro-Inverso Peptide Candidates for Treating Cardiac Amyloidosis
Scientists have used computational molecular dynamics simulations to identify two peptide candidates, DRI-R5S and DRI-H6A, that may disrupt the formation of Serum Amyloid A (SAA) fibrils linked to post-heart attack complications. The study builds on a hypothesis that SAA protein aggregates form after myocardial infarction and contribute to long-term cardiac damage in both mice and potentially humans. If validated experimentally, these drug candidates could represent a new therapeutic approach to reducing complications following heart attacks.
A new preprint study published on bioRxiv proposes four peptide drug candidates designed to interfere with the aggregation of Serum Amyloid A (SAA3) protein into fibrils, a process hypothesized to worsen long-term outcomes after myocardial infarction. The research is motivated by prior mouse model findings suggesting that SAA aggregates form in cardiac tissue following a heart attack and may drive chronic complications, with researchers speculating a parallel mechanism may exist in humans. To improve the durability of the peptides in the body, the team constructed them using D-amino acids — mirror-image versions of the naturally occurring L-amino acids — making them more resistant to enzymatic degradation. Using all-atom molecular dynamics simulations, the researchers evaluated how well each peptide destabilized existing SAA fibrils at the computational level. Two candidates, DRI-R5S and DRI-H6A, emerged as the most promising based on their simulated ability to disrupt fibril structure. The study is entirely computational at this stage and has not yet been tested in cell cultures, animal models, or human trials.
What's missing
The study relies solely on computational simulations and has not been validated through in vitro, in vivo, or clinical experiments. The underlying hypothesis that SAA aggregation drives post-infarction complications in humans remains unconfirmed, as the supporting evidence comes only from a mouse model. Key open questions include whether these peptides can reach cardiac tissue at therapeutic concentrations, whether they exhibit toxicity, and whether SAA fibril formation is causally linked to human cardiac outcomes rather than merely correlative.
What different sources said
- bioRxivCenter
D-Retro-Inverso Peptide Candidates for Inhibiting SAA Cardiac Amyloidosis
Related
Gut Bacteria Enzyme Found to Break Down Heat-Processed Food Compounds, Producing Novel Biogenic Amines
Researchers have discovered that an enzyme in common gut bacteria can degrade N-epsilon-carboxymethyllysine (CML), a compound formed during thermal food processing, producing previously unknown biogenic amines. The enzyme, ornithine decarboxylase SpeC from enterobacteria, acts on CML and related modified lysine derivatives through a low-level 'underground' catalytic activity. This finding suggests a previously unrecognized communication axis between thermally processed dietary compounds and gut microbial physiology, with potential implications for host health.
Full-Length Gene Sequencing Reveals Two Distinct Bacterial Communities in Black-Legged Ticks Expanding Into Canada
Researchers used Oxford Nanopore full-length 16S rRNA gene sequencing to characterize the microbiome of Ixodes scapularis black-legged ticks collected in Nova Scotia, Canada, distinguishing between tick-adapted bacteria and environmentally acquired bacteria. The study comes as I. scapularis — the primary vector of Lyme disease — is rapidly expanding northward into Canada due to climate change. The findings suggest that environmentally derived bacteria in tick microbiomes are not mere contamination, which has implications for how tick microbiome data is collected and interpreted across surveillance studies.
Study Identifies Metabolic Link Between Cell Envelope Stress and Biofilm Formation in Bacteria
Researchers have discovered that the metabolite acetyl-CoA directly inhibits enzymes that degrade the bacterial signaling molecule c-di-GMP, connecting cell envelope biosynthesis stress to biofilm formation in Pseudomonas aeruginosa. The study found that sub-inhibitory concentrations of antibiotics targeting early peptidoglycan biosynthesis — but not other antibiotic classes — elevate c-di-GMP levels by reducing phosphodiesterase activity, with acetyl-CoA competing for the enzyme active site. Because the relevant enzyme domain is broadly conserved across bacterial species, this checkpoint mechanism may be widespread and could have implications for understanding antibiotic-induced biofilm responses.