Density determination by analytical ultracentrifugation in a rapid dynamical gradient: application to lipid and detergent aggregates containing proteins

• Published in: Biochimica et biophysica acta Vol. 1115; no. 2; pp. 89 - 95
• Main Authors: Lustig, Ariel, Engel, Andreas, Zulauf, Martin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 06.12.1991; Elsevier
• Subjects: Analytical biochemistry: general aspects, technics, instrumentation; Analytical centrifugation; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Density; Detergents; Fundamental and applied biological sciences. Psychology; Lipid vesicle; Lipids - chemistry; Lipoprotein; Lipoproteins - chemistry; Membrane protein-lipid vesicle; Membrane Proteins - chemistry; Sucrose - chemistry; Temperature; Ultracentrifugation; Xenopus; D 2 O ≈ 2 H 2 O; Membrane protein-lipid vesicle; SBCT; Lipid vesicle; Lipoprotein; Nycodenz; Density; SB; RDDG; AU; POPC; SBDS; SBDS-BC; 8-POE; DMPC; Analytical centrifugation; Proteins; Detergent; Calcium antagonist; Liposome; Lipids; Density gradient; Artificial membrane; Ultracentrifugation; Limit; Method
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(91)90016-A

A rapidly developing dynamical gradient can be formed in the analytical centrifuge when a buffer solution prepared in D 2O is underlayered under the same buffer solution prepared in H 2O in a specially designed double sector cell. In a short time the boundary layer spreads to form the gradient. Heavy particles ( S ⩾ 10S) will band in the gradient corresponding to their density, which can be determined accurately. To this end, the buffer may contain density adjusting additives such as sucrose. We present results with this technique for lipid vesicles, for a Ca-antagonist bound to vesicles, as well as for a lipoprotein and reconstituted regular membrane protein-lipid arrays.