title: The formation of pepsin monomolecular layer by the Langmuir-Blodgett film deposition technique.
abstract: We report herein the formation of pepsin monomolecular layer by the Langmuir-Blodgett film deposition technique. An effort was made to find an optimal subphase by adjusting the concentration of salt (KCl) and pH by monitoring the growth kinetics of pepsin for the formation of Langmuir monolayer by using as little as possible pepsin molecules to build up ultra thin film and to measure the extent of denaturation. Significant changes of area/molecule, compressibility, rigidity and unfolding of pepsin are observed at optimized subphase than pure water subphase. Observations at optimal subphase are explained in context of the modified DLVO theory and the site dissociation model. FTIR analysis of amide band together with the observed surface morphology of pepsin film in FE-SEM images indicate that at optimal subphase the pepsin molecules modify their structures by incrementing the beta-structure, resulting into larger unfolding and inter-molecular aggregates.
authors.affiliation: Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
authors.forename: Prabir
authors.initials: P
authors.lastname: Pal
authors.forename: Tapanendu
authors.initials: T
authors.lastname: Kamilya
authors.forename: Mrityunjoy
authors.initials: M
authors.lastname: Mahato
authors.forename: G B
authors.initials: GB
authors.lastname: Talapatra
mesh_terms: D000327:Adsorption / Q000187:drug effects; D000465:Algorithms; D001272:Atmosphere / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010434:Pepsin A / Q000737:chemistry* / Q000648:ultrastructure; D044367:Phase Transition; D011189:Potassium Chloride / Q000737:chemistry / Q000494:pharmacology; D011489:Protein Denaturation; D017510:Protein Folding; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D014867:Water; D011189:Potassium Chloride; D010434:Pepsin A