Interaction of cysteine and its derivatives with monolayers of dipalmitoylphosphatidylcholine.

Interaction of cysteine and its derivatives with monolayers of dipalmitoylphosphatidylcholine. Colloids Surf B Biointerfaces. 2019 Oct 04;184:110548 Authors: Arias JM, Díaz SB, Ben Altabef A, Dupuy FG Abstract Molecular interactions between l-cysteine (Cys) and its ester derivatives (Cysx); l-cysteine ethyl ester (CE), l-cysteine methyl ester (CM) and N-acetyl l-cysteine (NAC) with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayers were investigated using Langmuir film balance technique. The effect of charge on monolayers made of cysteine and three ester derivatives with DPPC was investigated by working with un-buffered and buffered subphases. Also, the effects of cysteine derivatives interaction with DPPC monolayers were studied measuring the change in the surface tension upon aminoacid injection in the subphase whilst keeping lipid molecular density and lateral packing controlled. Cysteine and its ester derivatives showed interfacial activity reducing the air/water surface tension (πi) by 4 mN m-1. However, ester derivatives were able to insert into preformed DPPC monolayers at much higher surface pressures (Δπ), indicating a preferential interaction of Cysx with DPPC. The results indicate that, although the different derivatives of cysteine presented low surface activity, they were able to favourably interact with DPPC monolayers. Also, compression isotherms experiments in binary mixtures indicate that the more ...
Source: Colloids and Surfaces - Category: Biotechnology Authors: Tags: Colloids Surf B Biointerfaces Source Type: research