Details

Autor(en) / Beteiligte

• Fukushima, Kohsuke
• Muraoka, Yoshihiro
• Inoue, Tohru
• Shimozawa, Ryosuke

Titel

Conformational change of poly( l-lysine) induced by lipid vesicles of dilauroylphosphatidic acid

Ist Teil von

• Biophysical chemistry, 1988-07, Vol.30 (3), p.237-244

Ort / Verlag

London: Elsevier B.V

Erscheinungsjahr

1988

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• The effect of negatively charged dilauroylphosphatidic acid (DLPA) vesicles on the conformation of poly( L-lysine) was investigated by circular dichroism measurements. DLPA vesicles induced a confomiational change Of poly( L-lysine) from the random coil to β-structure in 5 mM Tes, pH 7.0. The fraction of induced β-structure ( F β) was determined via a procedure of curve fit the observed spectra to the reference spectra. F β increased linearly with the molar ratio, r, of DLPA to lysine residues up to r ⋍ 0.7, and reached a saturation value of 1 at r > 1. Within the range 0.7 ≲ r ≲ 1, precipitation occurred. The effect of dilution of the negative charge on vesicle membranes was examined by mixing DLPA with dilauroylphosphatidylcholine (DLPC). Although the β-structure Of poly L-lysine) was also induced by mixed vesicles, the saturation value of F β decreased with decreasing DLPA content in mixed vesicles. The variation in saturation value of F β with the composition of mixed vesicles was interpreted in terms of the change in average distance between DLPA head groups in mixed vesicles.