Open AccessRheumatoid factors from patients with rheumatoid arthritis react with Des‐Lys 58 ‐β 2 m, modified β 2 ‐microglobulin
Author(s) -
WILLIAMS R. C.,
NISSEN JR. M. H.,
MALONE C. C.
Publication year - 1993
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1993.tb03414.x
Subject(s) - beta (programming language) , beta 2 microglobulin , polyclonal antibodies , rheumatoid arthritis , chemistry , lysine , rheumatoid factor , reactivity (psychology) , immunology , amino acid , proline , stereochemistry , microbiology and biotechnology , biochemistry , antibody , medicine , biology , pathology , alternative medicine , computer science , programming language
SUMMARY Ten polyclonal IgM rheumatoid factor (RF) preparations, affinity‐purified from IgG columns, from patients with rheumatoid arthritis were studied for their ELISA reactivity with native β 2 m in parallel with Lys 58 ‐cleaved β 2 m and Des‐Lys 58 ‐β 2 m, the latter representing cleavage products of the native molecule present in some pathologic human sera. Most RF showed positive reactions with the native form of β 2 m but reduced reactivity for the cleaved forms of β 2 m. Reactions between cleaved β 2 m and RF, in solution, were demonstrated by inhibition of RF binding to native β 2 m by prcincubation with a range of concentrations of Dcs‐Lys 58 ‐β 2 m. By contrast, eight of nine murine MoAbs to human β 2 m showed approximately equivalent binding to native β 2 m, Lys 58 ‐cleaved β 2 m, and Des‐Lys 58 ‐β 2 m. Reactions between individual human RF and the altered forms of β 2 m (Lys 58 ‐cleaved β 2 m and Des‐Lys 58 ‐β 2 m) appeared to parallel the previously determined β 2 m single ammo acid specificities, in that RF’ showing strong reactivity with Lysine 58 also showed a significant diminished reactivity with the Des‐Lys 58 ‐β 2 m lacking the critical lysine residue. The present studies demonstrate that while human RF react with Lys 58 ‐cleaved β 2 m or Des‐Lys 58 ‐β 2 m, preferential reactivity is observed for native unaltered β 2 m.