It took two years to get a stable, crystalline form of the hepatitis C protease enzyme for study.

FORBES: Magazine Article

Peroxynitrites contribute to the hyperphosphorylation of tau proteins by oxidating g-protein coupled receptors and trysoine kinase receptors preventing protein kinase C and AKT from inactivating the enzyme GSK3 which is necessary to prevent the hyperphosphorylation of tau proteins.

FORBES: The Lessons Of Failure: What We Can Learn From Bapineuzumab's Blowup

Professor Seth Grant, an expert in the molecular mechanism of learning and memory at Edinburgh University, told BBC News Online that PKM was a particular version of an enzyme called protein kinase C (PKC) that had long been implicated in learning.

BBC: Scientists boost memory power