4E3U

Crystal Structure of Hen Egg White Lysozyme Cryoprotected in Proline

Summary for 4E3U

• Entry DOI: 10.2210/pdb4e3u/pdb
• Related: 4E3V 4E3W 4E3X
• Descriptor: Lysozyme C, PROLINE, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: hydrolase
• Biological source: Gallus gallus (bantam,chickens)
• Cellular location: Secreted: P00698
• Total number of polymer chains: 1
• Total formula weight: 14552.65

Authors

Tanner, J.J.,Pemberton, T.A. (deposition date: 2012-03-10, release date: 2012-07-25, Last modification date: 2024-11-06)

Primary citation

Pemberton, T.A.,Still, B.R.,Christensen, E.M.,Singh, H.,Srivastava, D.,Tanner, J.J.
Proline: Mother Nature's cryoprotectant applied to protein crystallography.
Acta Crystallogr.,Sect.D, 68:1010-1018, 2012

PubMed Abstract: L-Proline is one of Mother Nature's cryoprotectants. Plants and yeast accumulate proline under freeze-induced stress and the use of proline in the cryopreservation of biological samples is well established. Here, it is shown that L-proline is also a useful cryoprotectant for protein crystallography. Proline was used to prepare crystals of lysozyme, xylose isomerase, histidine acid phosphatase and 1-pyrroline-5-carboxylate dehydrogenase for low-temperature data collection. The crystallization solutions in these test cases included the commonly used precipitants ammonium sulfate, sodium chloride and polyethylene glycol and spanned the pH range 4.6-8.5. Thus, proline is compatible with typical protein-crystallization formulations. The proline concentration needed for cryoprotection of these crystals is in the range 2.0-3.0 M. Complete data sets were collected from the proline-protected crystals. Proline performed as well as traditional cryoprotectants based on the diffraction resolution and data-quality statistics. The structures were refined to assess the binding of proline to these proteins. As observed with traditional cryoprotectants such as glycerol and ethylene glycol, the electron-density maps clearly showed the presence of proline molecules bound to the protein. In two cases, histidine acid phosphatase and 1-pyrroline-5-carboxylate dehydrogenase, proline binds in the active site. It is concluded that L-proline is an effective cryoprotectant for protein crystallography.

PubMed: 22868767
DOI: 10.1107/S0907444912019580

Experimental method

X-RAY DIFFRACTION (1.5 Å)