Segmental flexibility of human myeloma immunoglobulins a

Mucosal Immunoglobulins

“…Although early work had questioned the level of flexibility in IgA (Weltman and Davis, 1970), fluorescence polarization and spin-label techniques later showed segmental flexibility in IgA to be comparable to that of IgG (Zagyansky and Gavrilova, 1974;Dudich et al, 1980;Liu et al, 1981).…”

Mucosal immunoglobulins

“…The angle between the Fab arms was seen to vary widely, and limited flexibility between the two Fc regions of S‐IgA was also observed (107, 109). Further evidence of flexibility was provided by techniques such as fluorescence polarization and spin‐labeling, which indicated that the segmental flexibility of IgA is comparable to that of IgG (110–112).…”

Spin-labeled carbohydrates

“…Comparison of the calculated values of aH for different conformations about the glycosidic bond with the observed oH values from their ESR spectra led to the conclusion that an eclipsed conformation (A) is the most stable.42 Also the configuration and steric requirements of substituents on C-d of the sugar moiety favored an eclipsed conformation. There was a correlation between the J2<a values from the NMR spectra of the dihydroxyimidazoline B series and the aH values from the ESR spectra of the nitronyl nitroxyl C series.42 For compounds with an axial substituent on C-/3 (114,115,120) there were high values for J2,« and aH while for compounds with equatorial substituents on C-/3 (117,121,122) the values for J2 a and aH were low.42 nitrophenol in methanol produced no nitroxyl radical. The same type of nitroxyl radical was obtained for the (m-nitrophenyl)glucoside as well as for the para and meta isomers of the corresponding galactosides.…”

“…The ESR spectra of the nitronyl nitroxyls [114][115][116][117][118][119][120][121][122][123][124][125][126][127] C and imino nitroxyls 114-127 D were analyzed in detail.42 For the former the two nitrogens are equivalent and aN1 = aN3 while for the latter the intensity of aN1 is double that of aN3. An interesting aspect of this work was the correlation of aH values of the sugar a proton with conformations about C-2 of the imidazoline ring of the C and D series (Figure 3).…”