Structure and orientation changes of omega- and gamma-gliadins at the air-water interface: a PM-IRRAS spectroscopy and Brewster angle microscopy study.
Microscopic and molecular structures of omega- and gamma-gliadin monolayers at the air-water interface were studied under compression by three complementary techniques: compression isotherms, polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), and Brewster angle microscopy (BAM). For high molecular areas, gliadin films are homogeneous, and a flat orientation of secondary structures relative to the interface is observed. With increasing compression, the nature and orientation of secondary structures changed to minimize the interfacial area. The gamma-gliadin film is the most stable at the air-water interface; its interfacial volume is constant with increasing compression, contrary to omega-gliadin films whose molecules are forced out of the interface. gamma-Gliadin stability at a high level of compression is interpreted by a stacking model.
Banc
Amélie
A
Centre de Recherche Paul Pascal, UPR 8641-CNRS, Avenue Albert Schweitzer, F-33600 Pessac.
Desbat
Bernard
B
Renard
Denis
D
Popineau
Yves
Y
Mangavel
Cécile
C
Navailles
Laurence
L
D000388:Air; D005903:Gliadin / Q000737:chemistry*; D008853:Microscopy / Q000379:methods*; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis / Q000379:methods*; D014867:Water
D014867:Water; D005903:Gliadin