Charge-Controlled Surface Properties of Native and Fluorophore-Labeled Bovine Serum Albumin at the Air-Water Interface.

ABSTRACT: Proteins at interfaces are important for protein formulations and in soft materials such as foam. Here, interfacial stability and physicochemical properties are key elements, which drive macroscopic foam properties through structure-property relations. Native and fluorescein isothiocyanate-labeled bovine serum albumin (BSA) were used to modify air-water interfaces as a function of pH. Characterizations were performed with tensiometry and sum-frequency generation (SFG). SFG spectra of O-H stretching vibrations reveal a phase reversal and a pronounced minimum in O-H intensity at pH values of 5.3 and 4.7 for native and labeled BSA, respectively. This minimum is attributed to the interfacial isoelectric point (IEP) and is accompanied by a minimum in surface tension and negligible ζ-potentials

SUBMITTER: Richert ME 

PROVIDER: S-EPMC6245422 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature