engleski

X-ray crystallography as a tool for analysis of biological macromolecules

X-ray diffraction analysis gives a lot of information about the molecular and crystal structure if single crystals of a compound can be obtained. For characterization of a compound, either a small molecule or a macromolecule, information about structure and properties is needed. Crstallization of proteins is often difficult and can be a bottleneck for such analysis. Some methods will be presented. Our newest results in protein crystallography will be briefly discussed: (1) enzymatic activity of tyrosine phenol-lyase (TPL) could be deduced by detailed structural analysis of native and mutated TPL forms in complexes with substrate analogues. Open and closed conformations were found in the structures giving insight into the enzymatic mechanism. Problems in defining molecular structure and formula of substrates from the electron density will be discussed ; (2) 3-hydroxyanthranilate 3, 4-dioxygenase, an enzyme that catalyzes the conversion of 3- hydroxyanthranilate to quinolinic acid, has been extracted and purified from bovine kidney, crystallized, and its structure determined at 2.5 Å resolution ; (3) coordination of iron in bovine insulin changed upon addition of bromide or iodide ions into crystallization solutions.

Bioanalysis; biological macromolecules

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