Artículos de revistas
Characterization And Determination Of Titratable Groups Of Proteins By Linearization Of Titration Curves. Ii. Application To Lysozyme
Analytical Biochemistry. , v. 123, n. 2, p. 244 - 248, 1982.
Hora Alves J.P.
The potentiometric acid-base titration curve of fully protonated lysozyme at ionic strengths of 0.10 and 1.0 m has been performed. The stoichiometry and the pKa values of each titratable group have been determined through the linearization of titration curves. Two types of carboxylic groups with pKa values of 3.76 and 5.02, the imidazole group with pKa 7.37 and the amine group with pKa 9.63, have been identified at an ionic strength of 0.10 m at 25.0°C. The number of titratable groups found per mole of protein has been 5.12 and 5.60 for the two types of carboxylic groups, 1.13 for the imidazole group, and 3.19 for the amino groups. The endpoint of the titration of the protein obtained by this method accords quite well with the endpoint obtained by the use of Gran function applied to the excess of strong base. © 1982.1232244248Godinho, Aleixo, (1981) Anal. Biochem, 112, pp. 323-328Cannan, Kibrick, Palmer, THE AMPHOTERIC PROPERTIES OF EGG ALBUMIN (1941) Annals of the New York Academy of Sciences, 41, pp. 243-266Tanford, Wagner, (1954) J. Amer. Chem. Soc, 76, pp. 3331-3336Beichok, Warner, Denaturation and Electrophoretic Behavior of Lysozyme1,2 (1959) Journal of the American Chemical Society, 81, pp. 1892-1897Pehrsson, Ingman, Axel, (1976) Talanta, 23, pp. 769-780Gran, (1952) Analyst (London), 77, pp. 661-671Canfield, (1963) J. Biol. Chem, 238, pp. 2698-2707Nozaki, Tanford, (1967) J. Biol. Chem, 242, pp. 4731-4735Godinho, O. E. S., Aleixo, L. M., and Hora Alves, J. P, paper to be published