Phage Langmuir monolayers and Langmuir–Blodgett films |
| |
Authors: | Rajesh Guntupalli Iryna Sorokulova Robert Long Eric Olsen William Neely Vitaly Vodyanoy |
| |
Institution: | 1. Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States;2. Clinical Research Laboratory, 81st Medical Group, Keesler AFB, MS 39534, United States;3. Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, United States |
| |
Abstract: | Stable, insoluble Langmuir monolayer films composed of Staphylococcus aureus-specific lytic bacteriophage were formed at an air–water interface and characterized. The phage monolayer was very strong, withstanding a surface pressure of ~40 mN/m at 20 °C. The surface pressure–area (Π–A) isotherm possessed a shoulder at ~7 × 104 nm2/phage particle, attributed to a change in phage orientation at the air–water interface from horizontal to vertical capsid-down/tail-up orientation as surface pressure was increased. The Π–A-dependence was accurately described using the Volmer equation of state, assuming horizontal orientation to an air–water interface at low surface pressures with an excluded area per phage particle of 4.6 × 104 nm2. At high pressures phage particles followed the space-filling densely packed disks model with a specific area of 8.5 × 103 nm2/phage particle. Lytic phage monolayers were transferred onto gold-coated silica substrates from the air–water interface at a constant surface pressure of 18 mN/m by Langmuir–Blodgett method, then dried and analyzed by scanning electron microscopy (SEM) and ellipsometry. Phage specific adsorption (Γ) in Langmuir–Blodgett (LB) films measured by SEM was consistent with that calculated independently from Π–A isotherms at the transfer surface pressure of 18 mN/m (Γ = 23 phage particles/μm2). The 50 nm-thickness of phage monolayer measured by ellipsometer agreed well with the horizontal phage average size estimated by SEM. Surface properties of phage Langmuir monolayer compare well with other monolayers formed from nano- and micro-particles at the air–water interface and similar to that of classic amphiphiles 1,2-diphytanoyl-sn-glycero-3-phosphocholine (phospholipid) and stearic acid. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|