User:NerdyShibari/sandbox

The guanylate-binding proteins (GBPs) form a family of proteins within the Dynamin superfamily of large GTPases. GBPs were originally found in human and murine fibroblast cells treated with interferon-α, interferon-β, or interferon-γ. Induction with interferon-γ results in a more specific and stronger expression of the GBP. The 67-kDa protein product of this induction has the unusual property of binding GMP, GDP, and GTP with similar affinities. Hydrolysis of GTP by the human guanylate-binding protein 1 (hGBP1) showed that the main product of hydrolysis is GMP and GDP is only a secondary product. Furthermore, no formation of pyrophosphate during hydrolysis was detected which is explained by a consecutive hydrolysis from GTP to GDP followed by a consecutive hydrolysis of GDP to GMP. While GMP is the main product of hGBP1 GTPase activity, hGBP2 showed GMP being a secondary product, and hGBP5 showed no detectable GMP formation.