The amphiphilic character of glycogenin

FEBS Letters

Carrizo, Marı́a E¹  Curtino, Juan A¹  Maggio, Bruno¹  Miozzo, Marı́a C¹ 

[1] Centro de Investigaciones en Quı́mica Biológica de Córdoba (CIQUIBIC), UNC-CONICET, Departamento de Quı́mica Biológica , Facultad de Ciencias Quı́micas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina

关键词: Glycogenin;    Proteoglycogen;    Glycogen;    Amphiphilicity;    Surface activity;    Surface pressure;    IPTG;    isopropylthiogalactopyranoside;    DTT;    dithiothreitol;    PMSF;    phenylmethylsulfonyl fluoride;    TLCK;    Nα-p-tosyl-L-lysine chloromethyl ketone;    PC;    phosphatidylcholine;    SDS-PAGE;    sodium dodecyl sulfate–polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(01)03192-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

This study describes for the first time the amphiphilicity of the protein moiety of proteoglycogen. Glycogenin but not proteoglycogen associates to phospholipid vesicles and forms by itself stable Gibbs and Langmuir monolayers at the air–buffer interface. The adsorption free energy (−6.7 kcal/mol) and the glycogenin collapse pressure (47 mN/m) are indicative of its high surface activity which can thermodynamically drive and retain the protein at the membrane interface to a maximum equilibrium adsorption surface pressure of 21 mN/m. The marked surface activity of glycogenin is further enhanced by its thermodynamically favorable penetration into zwitterionic and anionic phospholipids with a high cut-off surface pressure point above 30 mN/m. The strong association to phospholipid vesicles and the marked surface activity of glycogenin correspond to a high amphiphilic character which supports its spontaneous association to membrane interfaces, in which the de novo biosynthesis of glycogen was proposed to initiate.

【 授权许可】

Unknown