HSP Modulators: Methylene Blue

Methylene Blue Chemical Structure HSP70 Inhibitors and ModulatorsMethylene Blue

Heat Shock Protein 70/HSP70 Inhibitor

CAS Number: 61-73-4

Molecular Formula: C16H18ClN3S

Molecular Weight: 319.85 g/mol

Research Areas: Cancer Research, Heat Shock, Apoptosis

Alternative Names: N-(7-(dimethylamino)-3H-phenothiazin-3-ylidene)-N-methylmethanaminium chloride


Biological Description

Methylene blue irreversibly inhibits heat-shock inducible Hsp72 by oxidizing Cys306. It has no inhibitory effect against cytosolic constitutive heat shock cognate Hsc70. Methylene blue inhibits Hsp70 ATPase turnover rate, with EC50 of 80 uM. It reduces tau levels in engineered tau-overexpressed HeLa cells. Methylene blue is a pleiotropic molecule that is not selective for Hsp70.



  1. Jinwal UK, et al. Chemical Manipulation of Hsp70 ATPase Activity Regulates Tau Stability. J Neurosci. 2009;29(39):12079-88.
  2. Miyata et al., Cysteine reactivity distinguishes redox sensing by the heat-inducible and constitutive forms of heat shock protein 70. Chem Biol. 2012;19(11):1391-9.
  3. Thompson AD, et al. Analysis of the Tau-Associated Proteome Reveals That Exchange of Hsp70 for Hsp90 Is Involved in Tau Degradation. ACS Chem Biol. 2012;7(10):1677-86.