Neurotrophic activity of neudesin, a novel extracellular heme-binding protein, is dependent on the binding of heme to its cytochrome b5-like heme/steroid-binding domain.

摘要: Neudesin is a secreted protein with neurotrophic activity in neurons and undifferentiated neural cells. We report here that neudesin an extracellular heme-binding its dependent on the binding of heme to cytochrome b5-like heme/steroid-binding domain. At first, we found at least portion purified recombinant appeared bind hemin because solution was tinged green had sharp absorbance peak 402 nm. The addition exogenous extensively increased amount hemin-bound neudesin. In contrast, neudesinΔHBD, mutant lacking domain, could not hemin. bound (neudesin-hemin) significantly greater than either primary cultured or Neuro2a cells, suggesting depends enhanced by Fe(III)-protoporphyrin IX, but neither Fe(II)-protoporphyrin IX nor protoporphyrin alone. inhibition endogenous RNA interference decreased cell survival This indicates possibly contains experiment anti-neudesin antibody suggested detected culture medium cells associated it retained heme-affinity column all. first shows signal transducing itself. present findings may shed new light function proteins.