Effect of dense gas CO2 on the coacervation of elastin

Biomacromolecules. 2008 Apr;9(4):1100-5. doi: 10.1021/bm700891b. Epub 2008 Mar 26.


In this study for the first time the effect of high-pressure CO2 on the coacervation of alpha-elastin was investigated using analytical techniques including light spectroscopy and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic imaging and circular dichroism (CD) spectroscopy. The coacervation behavior of alpha-elastin, a protein biopolymer, was determined at temperatures below 40 degrees C and pressures lower than 180 bar. At these conditions elevated pressures did not disrupt the ability of alpha-elastin to coacervate. It was feasible to monitor the presence of amide I, II, and III bands for alpha-elastin at high-pressure CO2 using ATR-FTIR imaging. At a constant temperature the peak absorption was substantially enhanced by increasing the pressure of the system. CD analysis demonstrated the preservation of secondary structure attributes of alpha-elastin exposed to dense gas CO2 at the pressure range investigated in this study. The lower critical solution temperature of alpha-elastin was dramatically decreased from 37 to 16 degrees C when the CO2 pressure increased from 1 to 50 bar, without a significant change after that. Carbon dioxide at high pressures also impeded the reversible coacervation of alpha-elastin solution. These effects were predominantly associated with the lowered pH of the aqueous solution and maybe the interaction between CO2 and hydrophobic domains of alpha-elastin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amides / chemistry
  • Animals
  • Carbon Dioxide / pharmacology*
  • Cattle
  • Circular Dichroism / methods
  • Elastin / metabolism*
  • Pressure
  • Sodium Chloride / chemistry
  • Spectrophotometry, Infrared / methods
  • Spectroscopy, Fourier Transform Infrared / methods
  • Temperature


  • Amides
  • Carbon Dioxide
  • Sodium Chloride
  • Elastin