Comparison of acyl-carrier protein and other protein structures in aqueous solutions by Fourier-transform infrared spectroscopy.
Protein solution structures were analyzed by horizontal attenuated total reflectance (ATR) FTIR spectroscopy. Secondary structure compositions determined from analyses of amide-I and II region and amide-III region difference spectra were compared. Data for proteins of known solution structure, cytochrome c, concanavalin A and lysozyme, were compared with those reported in the literature. Melittin, a peptide from bee venom whose secondary structural configuration varies depending upon solution conditions was also examined. Acyl-carrier protein (ACP) is a small protein of recognized dynamic structure that in its diverse physiologic roles interacts specifically with numerous different proteins. Horizontal ATR FTIR analysis of ACP's secondary structure indicated a predominantly helical structure best defined as a combination of ordered and disordered helices. The FTIR-derived structural composition agreed with those determined for ACP by other techniques. Comparison of independent analyses of the amide-I and III regions to determine protein configuration compositions was a useful method of verifying the internal consistency of the calculated structural compositions of dynamically-structured proteins.
Ernst-Fonberg
M L
ML
Department of Biochemistry, James H. Quillen College of Medicine, East Tennessee State University, Johnson City 37614.
Worsham
L M
LM
Williams
S G
SG
D000213:Acyl Carrier Protein / Q000737:chemistry*; D000577:Amides / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008555:Melitten / Q000737:chemistry; D017433:Protein Structure, Secondary; D012996:Solutions; D013055:Spectrophotometry, Infrared / Q000379:methods
D000213:Acyl Carrier Protein; D000577:Amides; D012996:Solutions; D008555:Melitten