Study on maltose-neopentyl glycol-3 (MNG-3) at the air-aqueous subphase

Abstract

Maltose?neopentyl glycol-3 (MNG-3) shows favorable behavior relative to conventional detergents leading to enhanced structural stability and successful crystallization. Many researchers have been interested in conventional detergents because many proteins remain difficult to study owing to a lack of suitable detergents. The purpose of the experiment was focused to study the two dimensional characteristics of MNG-3 by Langmuir-Blodgett technique. Langmuir film and Langmuir-Blodgett film of MNG-3 were fabricated at the air-aqueous subphase and onto a solid substrate each. MNG-3 showed a unique surface pressure by different subphase conditions in surface pressure-area isotherm. To fine out the cause, surface pressure measurements (surface pressure-surface area isotherm, compression-expansion cycle) were invested to study the interaction in molecules and between molecule and subphase. And also AFM, STM and XRR were used for information and visualization of surface of MNG-3 layer, and then influence subphase was confirmed. These results suggested that combinations between the maltose of MNG-3 and water used as subphase enabled MNG-3 layer to endure high pressure and exist on denser layer at air-water interface and these combinations hindered transfer from the air-water interface to the hydrophilic substrate. But these combinations were blocked by carbonyl group of sodium carbonate.