TY - JOUR
T1 - Kinetics of a collagen-like polypeptide fragmentation after mid-IR free-electron laser ablation
AU - Zavalin, Andrey
AU - Hachey, David L.
AU - Sundaramoorthy, Munirathinam
AU - Banerjee, Surajit
AU - Morgan, Steven
AU - Feldman, Leonard
AU - Tolk, Norman
AU - Piston, David W.
N1 - Funding Information:
This work was supported by the Department of Defense Medical Free-Electron Laser Program (FA9550-04-1-0045 and F49620-00-1-0370) and by National Science Foundation/Human Resource Development (grant No. 0420516, the Center of Research Excellence in Science and Technology).
PY - 2008/8/1
Y1 - 2008/8/1
N2 - Tissue ablation with mid-infrared irradiation tuned to collagen vibrational modes results in minimal collateral damage. The hypothesis for this effect includes selective scission of protein molecules and excitation of surrounding water molecules, with the scission process currently favored. In this article, we describe the postablation infrared spectral decay kinetics in a model collagen-like peptide (Pro-Pro-Gly)10. We find that the decay is exponential with different decay times for other, simpler dipeptides. Furthermore, we find that collagen-like polypeptides, such as (Pro-Pro-Gly) 10, show multiple decay times, indicating multiple scission locations and cross-linking to form longer chain molecules. In combination with data from high-resolution mass spectrometry, we interpret these products to result from the generation of reactive intermediates, such as free radicals, cyanate ions, and isocyanic acid, which can form cross-links and protein adducts. Our results lead to a more complete explanation of the reduced collateral damage resulting from infrared laser irradiation through a mechanism involving cross-linking in which collagen-like molecules form a network of cross-linked fibers.
AB - Tissue ablation with mid-infrared irradiation tuned to collagen vibrational modes results in minimal collateral damage. The hypothesis for this effect includes selective scission of protein molecules and excitation of surrounding water molecules, with the scission process currently favored. In this article, we describe the postablation infrared spectral decay kinetics in a model collagen-like peptide (Pro-Pro-Gly)10. We find that the decay is exponential with different decay times for other, simpler dipeptides. Furthermore, we find that collagen-like polypeptides, such as (Pro-Pro-Gly) 10, show multiple decay times, indicating multiple scission locations and cross-linking to form longer chain molecules. In combination with data from high-resolution mass spectrometry, we interpret these products to result from the generation of reactive intermediates, such as free radicals, cyanate ions, and isocyanic acid, which can form cross-links and protein adducts. Our results lead to a more complete explanation of the reduced collateral damage resulting from infrared laser irradiation through a mechanism involving cross-linking in which collagen-like molecules form a network of cross-linked fibers.
UR - http://www.scopus.com/inward/record.url?scp=51049110764&partnerID=8YFLogxK
U2 - 10.1529/biophysj.107.122002
DO - 10.1529/biophysj.107.122002
M3 - Article
C2 - 18441025
AN - SCOPUS:51049110764
SN - 0006-3495
VL - 95
SP - 1371
EP - 1381
JO - Biophysical Journal
JF - Biophysical Journal
IS - 3
ER -