NEAXUSINSTITUTE OF BIODISCOVERY
Back to Research Hub
Flagship ProjectSTATUS: ExploringEVIDENCE // Preliminary
Gene: NPC1 | Chromosome 18q11.2
Flagship Research Specification

NPC1 Cholesterol Transport Dynamics & Lysosomal Trafficking

Niemann-Pick C1 (NPC1) is a 13-pass transmembrane lysosomal membrane protein essential for intracellular cholesterol export. Mutations in NPC1 lead to lysosomal lipid accumulation and progressive neurodegeneration. This project investigates variant-level conformational shifts using molecular dynamics simulations and machine learning residue contact graphs.

01 // Established Science

NPC1 is a 13-pass transmembrane protein acting downstream of NPC2 to export unesterified cholesterol from endolysosomes.

02 // Neaxus Hypothesis

Sterol sensing domain mutations alter allosteric coupling between luminal loop 1 and hydrophobic transmembrane channels.

03 // Simulation Result

GROMACS molecular dynamics (500ns) indicate p.I1061T increases local RMSF flexibility, impairing sterol transfer kinetics.

Key Computational Findings

  • 01.Simulations reveal structural rigidity in the luminal loop 1 interface when p.I1061T mutation is introduced.
  • 02.Residues 612–620 exhibit heightened RMSF fluctuations correlated with sterol binding pocket destabilization.
  • 03.Virtual screening identified 3 candidate hydrophobic stabilizer fragments targeting the sterol entry pore.

Limitations & In Silico Boundaries

  • !In silico dynamics performed without full lipid bilayer complexity.
  • !Kinetic rates are derived from simplified Markov state models without experimental cell-assay validation.
  • !Requires in vitro vesicle transfer validation.

Simulation Activity Stream

Discovery Activity

Methods & Datasets

METHODS USED
  • Molecular Dynamics Simulation (GROMACS)
  • AlphaFold3 Structural Ensemble Analysis
  • Evolutionary Variant Pathogenicity Scoring (ESM-1b)
  • Pathway Network Flux Modeling
REFERENCE DATASETS
  • PDB 3GKI / 5U74 Lysosomal Transporter Structures
  • ClinVar NPC1 Variant Repository
  • gnomAD v4 Exome Allele Frequency Matrix