Characterisation of the membrane affinity of an isoniazide peptide conjugate by tensiometry, atomic force microscopy and sum-frequency vibrational spectroscopy, using a phospholipid Langmuir monolayer modelElectronic supplementary information (ESI) available: Fitting parameters for the sum-frequency spectra. See DOI: 10.1039/c002737e

• Main Authors: Hill, Katalin, Pénzes, Csanád Botond, Schnöller, Donát, Horváti, Kata, B sze, Szilvia, Hudecz, Ferenc, Keszthelyi, Tamás, Kiss, Éva
• Format: Journal Article
• Language: English
• Published: 08.09.2010
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c002737e

Tensiometry, sum-frequency vibrational spectroscopy, and atomic force microscopy were employed to assess the cell penetration ability of a peptide conjugate of the antituberculotic agent isoniazide. Isoniazide was conjugated to peptide 91 SEFAYGSFVRTVSLPV 106 , a functional T-cell epitope of the immunodominant 16 kDa protein of Mycobacterium tuberculosis . As a simple but versatile model of the cell membrane a phospholipid Langmuir monolayer at the liquid/air interface was used. Changes induced in the structure of the phospholipid monolayer by injection of the peptide conjugate into the subphase were followed by tensiometry and sum-frequency vibrational spectroscopy. The drug penetrated lipid films were transferred to a solid support by the Langmuir-Blodgett technique, and their structures were characterized by atomic force microscopy. Peptide conjugation was found to strongly enhance the cell penetration ability of isoniazide. Increased membrane affinity of the antituberculotic agent isoniazide upon peptide conjugation is revealed by tensiometry, sum-frequency spectroscopy, and AFM.