FTIR and VCD

At HTL Biosolutions, Inc., we offer both consulting and contract research services on protein characterizations, stability testings and formulation development.

FTIR spectroscopy is one of the most widely used biophysical techniques to study protein secondary structures and conformational dynamics (H-D exchange). At HTL Biosolutions Inc., we have the state of art FTIR spectrometer that offers spectral resolution as high as 0.5 cm-1, and the capability to perform rapid scan and surface FTIR microscopy.

Key Benefits of using FTIR:
- Comparability study of lot-to-lot variations.
- Protein secondary structure analysis (alpha-helix, beta-sheet, beta-turns, and irregular/random coil)
- Determination of parallel and anti-parallel beta-sheets
- Protein conformational dynamics by H-D exchange
- Protein conformational stability (thermodynamic stability and kinetic stability)
- Identification of particles to be proteinatious or not





Capabilities
Our FTIR spectrometer is equipped with a wide range of accessories including transmission, ATR and diffused reflectance apparatus. We can analyze protein samples in virtually all physical states including liquid, gel, solid and colloid states. With IR microscope, particles in solutions can be identified if they are of protein nature or not.

Transmission FTIR
Protein samples in solutions are usually placed between two CaF2 windows with defined window path-length during data collection. For protein solid samples, they are usually mixed with certain amount of KBr salt to prepare a pellet from which FTIR data can be collected.  

ATR FTIR
Protein samples (solution or solid) are usually placed on the surface of a ZnSe crystal or a diamond mounted on an ATR device when FTIR data are collected.

Diffused Reflectance FTIR
This technique is particularly useful to analyze solid protein samples without any sample processing. Protein solid samples are usually placed into a sample holder during data collection.



References

1. Li, T. Investigation of Protein-Protein Interactions by Isotope Edited Fourier Transformed Infrared Spectroscopy. Spectroscopy, 18, 397-406, 2004.

2. Li, T., Talvenheimo, J., Zeni, L., Rosenfield, R., Stearns, G. and Arakawa, T. Changes in Protein Conformation and Dynamics upon BDNF/trkB Complex Formation: An Investigation by Isotope-Edited FTIR Spectroscopy. Biopolymers, 67(1), 10-19, 2002.

(c) 2008 HTL Biosolutions Inc.