Why do we study protein crystallization?

	Lumazine synthase has spherical molecule However, readily forms chains However, 2D crystals cleave along molecular rows
	Suggests anisotropy,
	not revealed by x-ray structure

Protein condensation diseases

Sickle cell disease is associated with the formation of ordered aggregates in the red blood cells

Protein crystals are used as pharmaceutical preparations

	Insulin, growth hormone, erythropoetin, interferon
	Uniform crystallite size needed for sustained release Achievable through control of nucleation

X-ray, neutron and electron crystallography require large, high quality crystals

Understanding of growth mechanisms may prompt strategies for improvement of crystallization conditions