Crystallization of PNMT, the adrenalinesynthesizing enzyme, is critically dependent on a high protein concentraition

Abstract

Phenylethanolamine N-methyltransferase, PNMT, utilizes the methylating cofactor S-adenosyl-L-methionine to catalyse the synthesis of adrenaline. Human PNMT has been crystallized in complex with an inhibitor and the cofactor product S-adenosyl-L-homocysteine using the hanging-drop technique with PEG 6000 and lithium chloride as precipitant. A critical requirement for crystallization was a high enzyme concentration (>90 mg ml-1) and cryocrystallography was used for high-quality data measurement. Diffraction data measured from a cryocooled crystal extend to a resolution of 2.3 Å. Cryocooled crystals belong to space group P43212 and have unit-cell parameters a = b = 94.3, c = 187.7 Å.