title: Formation of a DNA layer on Langmuir-Blodgett films and its enzymatic digestion.
abstract: Here, we report a system we have developed where long double-stranded DNAs (dsDNAs) are immobilized on a monolayer of Zn-arachidate. We have applied the Langmuir-Blodgett technique to form the monolayer of Zn-arachidate where Zn(II) is bound to arachidic acid through charge neutralization. Because tetrahedral Zn(II) participates in DNA recognition through coordination, we have been able to layer DNA over the Zn-arachidate monolayer. The DNA layer shows a typical compression and expansion cycle in a concentration-dependent fashion. Interestingly, the DNA monolayer is available for enzymatic degradation by DNaseI. The detection of DNA and its accessibility towards biological reaction is demonstrated by imaging through fluorescence microscopy. The conformation of the DNA, immobilized on the monolayer, was studied with the help of atomic force microscopy (AFM). We observed that the dsDNAs were aligned in a stretched manner on the surface. To investigate further, we also demonstrate here that the small single-stranded DNA (ssDNA) immobilized on the air-water interface can act as a target molecule for the complementary ssDNA present in the subphase. The study of DNA hybridization done with the help of fluorescence spectroscopy clearly supports the AFM characterization.
authors.affiliation: Department of Physics and Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India.
authors.forename: Anusarka
authors.initials: A
authors.lastname: Bhaumik
authors.forename: Madhugiri
authors.initials: M
authors.lastname: Ramakanth
authors.forename: Loveleen Kaur
authors.initials: LK
authors.lastname: Brar
authors.forename: Arup K
authors.initials: AK
authors.lastname: Raychaudhuri
authors.forename: Francis
authors.initials: F
authors.lastname: Rondelez
authors.forename: Dipankar
authors.initials: D
authors.lastname: Chatterji
mesh_terms: D004269:DNA, Bacterial / Q000737:chemistry*; D003850:Deoxyribonuclease I / Q000737:chemistry*; D004537:Eicosanoic Acids / Q000737:chemistry; D005898:Glass / Q000737:chemistry; D008567:Membranes, Artificial; D013499:Surface Properties; D015032:Zinc / Q000737:chemistry
chemical_list: D004269:DNA, Bacterial; D004537:Eicosanoic Acids; D008567:Membranes, Artificial; D003850:Deoxyribonuclease I; D015032:Zinc; C094477:arachidic acid