Gallium Nitrate | Encyclopeptide

Chemical Identity

Property	Value
Chemical Formula	Ga(NO3)3
Molecular Weight	255.7 Da
CAS Number	13494-90-1
Peptide Class	Metal Salt
Route	IV infusion

Structure

Gallium nitrate is an inorganic gallium(III) salt. While not a peptide itself, it represents an important class of metal-based therapeutics that exploit metal-peptide interactions for therapeutic benefit. Gallium competes with iron for binding to transferrin and iron-dependent enzymes.

Mechanism of Action

Gallium inhibits ribonucleotide reductase, the enzyme that converts ribonucleotides to deoxyribonucleotides for DNA synthesis, by displacing iron from the enzyme’s R2 subunit. It also inhibits cellular iron uptake by binding transferrin, and disrupts mitochondrial function by inhibiting iron-sulfur enzymes. In bone, gallium reduces osteoclastic bone resorption.

Clinical Applications

Cancer-related hypercalcemia: FDA-approved indication
Non-Hodgkin lymphoma: Investigational combinations
Bladder cancer: Intravesical therapy (investigational)
Bone metastases: Anti-resorptive effect

Pharmacokinetics

Half-life: 24 hours
Protein binding: Minimal (primarily transferrin-bound)
Elimination: Renal (95% unchanged)
Dose adjustment: Required in renal impairment
Route: IV continuous infusion (5-7 days)

Safety and Side Effects

Nephrotoxicity (dose-limiting), optic neuritis (rare), anemia (iron-dependent), nausea, and hypotension. Adequate hydration required. Audiometry monitoring recommended with prolonged use.

References

Warrell, R.P., et al. (1991). Gallium nitrate for hypercalcemia. Journal of Clinical Oncology, 9, 1902-1912.
Chitambar, C.R. (2010). Gallium compounds as antineoplastic agents. Current Opinion in Oncology, 22, 582-588.