Conformational stability of fructose-1, 6-biphosphate aldolase from Ceratitis capitata.
Fructose 1, 6-biphosphate aldolase from Ceratitis capitata is a tetramer of identical subunits with 34% alpha-helix, 22% beta structure and 44% of aperiodic order. Increase of urea concentration up to 4.0 M results in non-cooperative reversible dissociation of the enzyme. Sodium dodecylsulphate 0.06% (w/v) dissociates the tetramer cooperatively with retention of the helical content. Thermal denaturation was a non-reversible cooperative process with a midpoint for the transition at 55 degrees. Cysteine residues are involved in this process and 2-mercaptoethanol preserves partially the enzyme activity. The acidic dissociation of the enzyme is a non-reversible process in contrast to the reversible basic dissociation. Increase of ionic strength results in a more ordered secondary structure for the monomer after acidic dissociation.
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D004175:Diptera / Q000201:enzymology*; D005634:Fructose-Bisphosphate Aldolase; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008623:Mercaptoethanol; D009994:Osmolar Concentration; D011487:Protein Conformation; D012967:Sodium Dodecyl Sulfate; D013696:Temperature; D014508:Urea
D046911:Macromolecular Substances; D012967:Sodium Dodecyl Sulfate; D008623:Mercaptoethanol; D014508:Urea; D005634:Fructose-Bisphosphate Aldolase