Large-scale purification and biochemical characterization of crystallization-grade porin protein P from Pseudomonas aeruginosa.
Article Details
- CitationCopy to clipboard
Worobec EA, Martin NL, McCubbin WD, Kay CM, Brayer GD, Hancock RE
Large-scale purification and biochemical characterization of crystallization-grade porin protein P from Pseudomonas aeruginosa.
Biochim Biophys Acta. 1988 Apr 7;939(2):366-74.
- PubMed ID
- 2451538 [ View in PubMed]
- Abstract
A large-scale purification scheme was developed for lipopolysaccharide-free protein P, the phosphate-starvation-inducible outer-membrane porin from Pseudomonas aeruginosa. This highly purified protein P was used to successfully form hexagonal crystals in the presence of n-octyl-beta-glucopyranoside. Amino-acid analysis indicated that protein P had a similar composition to other bacterial outer membrane proteins, containing a high percentage (50%) of hydrophilic residues. The amino-terminal sequence of this protein, although not homologous to either outer membrane protein, PhoE or OmpF, of Escherichia coli, was found to have an analogous protein-folding pattern. Protein P in the native trimer form was capable of maintaining a stable functional trimer after proteinase cleavage. This suggested the existence of a strongly associated tertiary and quaternary structure. Circular dichroism studies confirmed these results in that a large proportion of the protein structure was determined to be beta-sheet and resistant to acid pH and heating in 0.1% sodium dodecyl sulphate.