The role of formic acid in solution stability and crystallization of silk protein polymer.
In this paper, the regenerated silk fibroin (SF) solution dissolved in formic acid was used as a model protein to understand the role of formic acid in solution stability and crystallization of protein-based materials. The molecular decomposition of SF did not occur for the dissolution process in formic acid within 1-2 days of storage times. The beta-sheet crystallization of SF molecules was occurred by the elimination of formic acid upon drying. The SF molecules in formic acid solution are stable and have low hydrodynamic radius values. This may be closely related to the fact that formic acid has two opposite functions of dissolution and crystallization simultaneously. The turbidity, dynamic light scattering and FTIR measurements elucidate that the solution stability and crystallization of SF are attributed to compact molecular shape of SF in formic acid, resulted from the molecular interactions between formic acid and polar groups in SF molecules.
Um
In Chul
IC
Department of Natural Fiber Sciences, Seoul National University, Suwon 441-744, South Korea.
Kweon
Hae Yong
HY
Lee
Kwang Gill
KG
Park
Young Hwan
YH
D003460:Crystallization; D004591:Electrophoresis, Polyacrylamide Gel; D005349:Fibroins / Q000737:chemistry*; D005561:Formates / Q000737:chemistry*; D019476:Insect Proteins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011487:Protein Conformation; D047011:Silk; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared
D005561:Formates; D019476:Insect Proteins; D047011:Silk; D012996:Solutions; C030544:formic acid; D005349:Fibroins