1-Anilino-8-naphthalene sulfonate anion-protein binding depends primarily on ion pair formation.
Biophys J
; 74(1): 422-9, 1998 Jan.
Article
em En
| MEDLINE
| ID: mdl-9449342
ABSTRACT
The ANS- (1-anilino-8-naphthalene sulfonate) anion is strongly, dominantly bound to cationic groups of water-soluble proteins and polyamino acids through ion pair formation. This mode of ANS- binding, broad and pH dependent, is expressed by the quite rigorous stoichiometry of ANS- bound with respect to the available summed number of H+ titrated lysine, histidine, and arginine groups. By titration calorimetry, the integral or overall enthalpies of ANS- binding to four proteins, bovine serum albumin, lysozyme, papain, and protease omega, were arithmetic sums of individual ANS(-)-polyamino acid sidechain binding enthalpies (polyhistidine, polyarginine, polylysine), weighted by numbers of such cationic groups of each protein (additivity of binding enthalpies). ANS- binding energetics to both classes of macromolecules, cationic proteins and synthetic cationic polyamino acids, is reinforced by the organic moiety (anilinonaphthalene) of ANS-. In a much narrower range of binding, where ANS- is sometimes assumed to act as a hydrophobic probe, ANS- may become fluorescent. However, the broad overall range is sharply dependent on electrostatic, ion pair formation, where the organic sulfonate group is the major determinant of binding.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Soroalbumina Bovina
/
Papaína
/
Muramidase
/
Histidina
/
Naftalenossulfonato de Anilina
Limite:
Animals
Idioma:
En
Revista:
Biophys J
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos