Rheological properties of regular insulin and aspart insulin Langmuir monolayers at the air/water interface: condensing effect of Zn2+ in the subphase.
Colloids Surf B Biointerfaces
; 115: 219-28, 2014 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-24362061
The interfacial behavior of regular insulin (Reg-insulin) and aspart insulin (Asp-insulin) was critically affected by the presence of Zn(2+) in the subphase. This cation induced a condensed-like behavior in the compression isotherms, especially apparent for Reg-insulin films when observed by Brewster angle microscopy. Immediately after spreading, Reg-insulin, but not Asp-insulin, showed bright patches that moved in a gaseous-like state. Moreover, Zn(2+) caused marked variations of the surface electrostatics of both insulin monolayers and considerable hysteresis of their molecular organization. By oscillatory compression-expansion cycles, we observed in all cases the development of a dilatational response to the surface perturbation, and both monolayers exhibited well-defined shear moduli in the presence of Zn(2+), which was higher for Reg-insulin. Development of a shear modulus indicates behavior resembling a nominal solid, more apparent for Reg-insulin than for Asp-insulin, suggesting the presence of viscoelastic networks at the surface.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Reologia
/
Zinco
/
Água
/
Ar
/
Insulina Aspart
/
Insulina
Limite:
Humans
Idioma:
En
Revista:
Colloids Surf B Biointerfaces
Assunto da revista:
QUIMICA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Holanda