Rheological properties of regular insulin and aspart insulin Langmuir monolayers at the air/water interface: Condensing effect of Zn2+ in the subphase
The interfacial behavior of regular insulin (Reg-insulin) and aspart insulin (Asp-insulin) was critically affected by the presence of Zn2+ in the subphase. This cation induced a condensed-like behavior in the compression isotherms, especially apparent for Reg-insulin films when observed by Brewster...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2014 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/32039 |
| Acceso en línea: | http://hdl.handle.net/11336/32039 |
| Access Level: | acceso abierto |
| Palabra clave: | Langmuir Monolayer Regular Insulin Aspart Insulin Surface Behavior Surface Rheology https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Sumario: | The interfacial behavior of regular insulin (Reg-insulin) and aspart insulin (Asp-insulin) was critically affected by the presence of Zn2+ 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, Zn2+ 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 Zn2+, 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. |
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