[A comparative structural analysis of Fab-fragments of monoclonal rheumatoid and non-rheumatoid immunoglobulins M].
The spin-labeling method was used to study the Fab- and Fab-RF-fragments of IgM and IgM-RF, respectively. The spin-label 2,2,6,6-tetramethyl-4-dichloro-sym-triazinyl-aminopiperidine-1-oxyl was introduced into the peptide moiety of the proteins. The rotational correlation time t of the spin-label carrier was determined based on the temperature-viscosity dependence of the EPR spectra parameters of the spin-labeled proteins. The tau values for Fab- and Fab-RF-fragments were 21 +/- 2 and 12 +/- 1 ns, respectively. The data strongly suggest that the significantly lower tau value for the Fab-RF-fragment may be due to the local structural flexibility of the fragment, which in turn may explain the peculiarities of IgM-RF as an autoantibody.
Timofeev
V P
VP
Tkachev
Ia V
IaV
Novikov
V V
VV
Varlamova
E Iu
EIu
Lapuk
V A
VA
D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry*; D007075:Immunoglobulin M / Q000737:chemistry*; D012217:Rheumatoid Factor / Q000737:chemistry*
D007140:Immunoglobulin Fab Fragments; D007075:Immunoglobulin M; D012217:Rheumatoid Factor