[Luminescent analysis of the structure of human alpha-1-microglobulin].
The spectra of absorption, fluorescence, and excitation of fluorescence of preparations of alpha-1-microglobulin isolated from human urea by two methods, gel chromatography and immunoaffinity chromatography with additional purification by activated charcoal, have been investigated in ultraviolet and visible regions. A possible nature of low-molecular compounds coloring alpha-1-microglobulin yellow-brown and their role in stabilizing the structure of protein globule are discussed. The action of urea (1.0-10 M) and guanidine hydrochloride (0.25-6 M) on the conformational state and the fast (nanosecond) internal dynamics of alpha-1-microglobulin has been investigated by the method of tryptophan fluorescence. It has been shown that the unfolding of alpha-1-microglobulin under the action of these denaturants is associated with a significant increase in the nanosecond internal dynamics of protein. The ability of alpha-1-microglobulin to restore the initial conformation characteristic for the native protein and the internal dynamics after the unfolding of the globule by 10 M urea and 6 M guanidine hydrochloride has been ascertained. It has been found that alpha-1-microglobulin isolated by the method of gel chromatography can exist in solution of 4-6 M urea in a thermodynamically stabile partialy folded state.
Mazhul'
V M
VM
Kananovich
S Zh
SZh
Serchenia
T S
TS
Sviridov
O V
OV
D000510:Alpha-Globulins / Q000737:chemistry* / Q000302:isolation & purification / Q000652:urine; D002850:Chromatography, Gel; D005453:Fluorescence; D019791:Guanidine / Q000737:chemistry; D006801:Humans; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D013050:Spectrometry, Fluorescence; D014508:Urea / Q000737:chemistry
D000510:Alpha-Globulins; C016001:alpha-1-microglobulin; D014508:Urea; D019791:Guanidine