[Regulation of the orientation of the IgG and IgM molecule at the interface].

Pathological immunoglobulins (IgG from patients with multiple myeloma and IgM from patients with Waldenström macroglobulinemia) have been shown to possess hydrophylic-lipophylic balance (HLB) which differed from normal Ig HLB. HLB deficiency in pathological proteins was due to the increase of hydrophobic area at the surface of protein globe, which was the reason for different normal and abnormal Ig orientations at the aqueous NaCl solution--air interface. The normal IgG and IgM had horizontal orientation while abnormal ones had vertical orientation. Both normal and abnormal Ig changed their orientation in monolayers as a result of sodium deoxycholate processing. The change in orientation depended on protein molecules interaction with single molecules or micelles of sodium deoxycholate.