Raman studies of L-Cysteine. HCl interaction with DPPC membranes

J. M. ARIAS; A. BEN ALTABEF; M. E. TUTTOLOMONDO; S. B. DIAZ

Fortaleza

Congreso; ICORS2016; 2016

Interactions of L-cysteinehydrochloride (Cys), a bioactive cysteine derivative,with dipalmitoyl phosphatidylcholine (DPPC) were investigated. To gain a deeper insight in analyzing L-cysteineethyl ester. HCl interaction with liposomes of dipalmitoylphosphatidylcholine(DPPC) in anhydrous and hydrated states we performed experimental studies by Ramanspectroscopy. Previous FTIR results [1] for L-cysteine show a differentiated effect inthe hydrophilic region. Since it dehydrates the phosphate group, Cys interactswith the C = O groups replacing structured water with formation of hydrogen bondin both populations, in anhydrous state. A displacement is observed inthe water molecules, both in gel and liquid crystalline state, in theinterphase region. There is no subsequent formation of hydrogen bonds for bothpopulations of the C=O group. The Cys effect on the phosphate group is observedin the hydrophilic region of the lipid polar head: the Cys?PO2-interaction would be higher than the H2O?PO2-interaction replacing the hydration water molecules more easily than in theliquid crystalline state.