Characterization of Three Feline Paraproteins

[摘要] Serum protein electrophoretic studies on three cats, two with lymphosarcoma and one with multiple myeloma, revealed M components in the γ region. These proteins were isolated by zone electrophoresis and were characterized immunologically, physically and chemically. Antisera to two feline isolates demonstrated individual antigenic specificity. All three proteins were classified as γG lambda immunoglobulins on the basis of cross-reactivities with human antisera. Cross-reactions were also documented between each of the feline proteins and previously studied canine light chains and intact human γG proteins. By analytical ultracentrifugation these feline immunoglobulins had Svedberg constants of approximately 6.8S. Molecular weight determinations of the intact γG proteins by SDS acrylamide gel analysis indicated an average m.w. of 154,000. The amino terminal amino acid residue of one of the feline heavy chains was glutamic acid and that of another aspartic acid. Thus these chains could be partially sequenced by an automatic protein sequencer. Comparison of the results with sequences of human VHIII heavy chains showed a striking sequence homology between the two species.

[学科分类] 生物科学（综合）