Computational Study Reveals Natural Light-Harvesting Complexes Minimize Disorder for Optimal Energy Transfer
Researchers used advanced molecular dynamics simulations to compare the natural 9-fold symmetric light harvesting 2 (LH2) complex with computationally designed 6- and 12-fold variants. The natural structure exhibits significantly lower energetic disorder and better-preserved hydrogen bonding networks compared to the synthetic alternatives. This finding suggests that nature's design of LH2 complexes prioritizes disorder minimization as a key principle for achieving high energy conversion efficiency.
A new computational study published on arXiv examined why the light harvesting 2 (LH2) complex found in purple bacteria achieves such high energy conversion efficiency. Researchers conducted all-atomistic molecular dynamics simulations comparing the natural 9-fold symmetric LH2 complex with two hypothetical non-natural variants featuring 6- and 12-fold symmetries. Using a combination of interpolation methods for potential energy surfaces and neural network machine learning, they analyzed the dynamical and statistical properties of electronic excited states in pigment molecules across all three structures. The results demonstrated that non-natural LH2 variants exhibited substantially greater quasistatic disorder and more disrupted hydrogen bonding networks, while local environmental dynamics remained relatively unchanged. These findings provide direct computational evidence that the natural structure and size of LH2 complexes are optimized to minimize energetic disorder, a design principle that appears fundamental to their superior energy transfer capabilities.
What's missing
The study's limitations include reliance on computational modeling rather than experimental validation of the synthetic variants, and the scope is limited to structural comparisons without exploring other potential design principles or evolutionary factors that may have shaped natural LH2 complexes.
What different sources said
- arXiv physicsCenter
Minimization of disorder as a key design principle for natural sizes of light harvesting 2 complexes
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.