|Title||Enhancing protein crystallization through precipitant synergy.|
|Publication Type||Journal Article|
|Year of Publication||2003|
|Authors||Majeed, S, Ofek, GA, Belachew, A, Huang, C-chin, Zhou, T, Kwong, PD|
|Date Published||2003 Sep|
|Keywords||Animals, Chemical Precipitation, Chickens, Crystallization, Crystallography, X-Ray, Models, Molecular, Muramidase, Protein Conformation, Proteins|
Suitable conditions for protein crystallization are commonly identified by screening combinations of independent factors that affect crystal formation. Because precipitating agents are prime determinants of crystallization, we investigated whether a systematic exploration of combinations of mechanistically distinct precipitants would enhance crystallization. A crystallization screen containing 64 precipitant mixtures was devised. Tests with ten HIV envelope-related proteins demonstrated that use of precipitant mixtures significantly enhanced both the probability of crystallization as well as the quality of optimized crystals. Tests with hen egg white lysozyme generated a novel C2 crystal from a salt/organic solvent mixture; structure solution at 2 A resolution revealed a lattice held together by both hydrophobic and electrostatic dyad interactions. The results indicate that mechanistically distinct precipitants can synergize, with precipitant combinations adding unique dimensions to protein crystallization.