Biology subjects

Damani, V.

Publications and source records attributed to Damani, V..

3 recordsLinked to original sources

bioRxiv2026

Expression and Engineering of Conductive Cytochrome Nanowires

Electrically conductive protein nanowires produced by metal-reducing bacteria have attracted interest as sustainable electronic materials, but their study and engineering have been limited by difficulties in expression, purification, and genetic manipulation. Here we establish Shewanella oneidensis as a heterologous host for production of Geobacter sulfurreducens OmcZ nanowires and progress a complementary in vitro assembly strategy that yields highly pure nanowire preparations. This platform enabled systematic engineering of OmcZ, revealing extensive tolerance to sequence variation and faciliating the design of enhanced-conductivity variants. Guided by comparative analysis of environmental OmcZ homologs, we generated a chimeric nanowire, OmcZ+, that exhibited a [~]3.5-fold increase in bulk conductivity while retaining the overall structure of the parent nanowire. Cryo-electron microscopy revealed unexpected architectural plasticity in OmcZ+ wires, including non-linear dendritic and pentameric assemblies mediated by the solvent-exposed heme VII, suggesting previously unrecognized modes of cytochrome nanowire organization. Incorporation of engineered OmcZ variants into water evaporation-induced electricity generators produced power densities up to [~]25.3 W cm-{superscript 2} and enabled high-performance operation in saline environments, including seawater and human sweat. Together, these results establish a versatile platform for the production, structural analysis, and engineering of cytochrome nanowires, providing a foundation for the development of programmable biological electronic materials.

bioengineering↗

bioRxiv2026

Quorum-Sensing-Mediated Extracellular Electron Transfer Enables Hydrogel Morphogenesis

Engineered living materials seek to capture the sensitivity, responsiveness, and programmable characteristics of biological systems. One emergent property of living systems is genetically driven spatial patterning, which controls cell differentiation and the development of complex multicellular organisms. Inspired by this capability, we use bacteria to spatially control material assembly. In our system, extracellular electron transfer (EET) flux from Shewanella oneidensis drives hydrogel synthesis via copper-catalyzed radical polymerization. We first construct a recombinant quorum sensing system in S. oneidensis that allows for cell-cell communication between "sender" and "receiver" cells through an autoinducer. We then examine controlled gene expression and EET-driven chemical transformation in various synthetic consortia. Via diffusion through agarose, we examine 2D patterns of gene expression relative to localized sender cell populations and demonstrate controlled hydrogel crosslinking in predictable patterns. Finally, we apply computational methods and NOT logic in "receiver" cells towards more complex patterns of gene expression. Our results highlight the potential of bacteria to program material systems with life-like properties including self-assembly, environmental responsiveness, and patterned differentiation.

Synthetic Biology↗

bioRxiv2022

Targeted Sequencing of Alzheimers Disease Genes in Gujarat Cohort

Alzheimers Disease (AD) is the most common type of dementia affecting cognitive and behavioural functions. Its a complex disease that results from the modest effect of gene interaction and environmental factors, as a result of which its exact pathogenesis is still unknown. In the present study, we have performed an association study of exonic regions of 94 genes with AD using the Haloplex target enrichment method and genotyping of 4 genes NOTCH4(rs367398), NEP(rs61760379), APOE (rs121918398), and ATP7B(rs1801243) using PCR RFLP technique. In this study, we screened 32 AD cases and 11 control samples. We have identified 19 variants assigned to 16 genes that were significantly associated with AD with a p-value < 0.05. However, no variants have passed multiple test corrections except NOTCH4/rs367398 genotyped using the PCR-RFLP approach. The functional enrichment analysis of the significant genes for the disease indicates that the genes are significantly involved in AD. Also, functional enrichment analysis for biological processes using ClueGo and network analysis using the STRING database indicated that the genes are directly and indirectly playing a role in AD pathogenesis. The eQTL analysis of the variants with GTEx dataset indicate that out of 19 variants ACHE/rs1799806 and NOTCH4/rs367398 variants is showing significant eQTL for the neighbouring genes for different brain regions and whole blood. Regardless, additional studies with a large cohort are required to establish the role and prevalence of these variants in the local population of Gujarat.

genomics↗