Comparative study of monoclonal immunoglobulin M and rheumatoid immunoglobulin M by differential scanning microcalorimetry.
Thermal denaturation of monoclonal immunoglobulin M (IgM) and rheumatoid immunoglobulin M (IgM-RF) and their Fab- and (Fc)5-fragments was studied by differential scanning microcalorimetry. The melting of IgM-RF started at a higher temperature than that of IgM and the maximum temperature of its main asymmetric peak of heat absorption was higher by 4 degrees C. At equal values of enthalpy, the thermal denaturation of IgM-RF and IgM consisted of four and five individual transitions, respectively, between pairs of states. The comparison of thermal denaturation parameters of Fab- and (Fc)5-fragments of IgM-RF and IgM showed a thermodynamic similarity of (Fc)5-fragments of both proteins, while their Fab-fragments differed in the interaction between VL-CL and VH-CH domains.
Protasevich
I I
II
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
Ranjbar
B
B
Varlamova EYu
Cherkasov
I A
IA
Lapuk
V A
VA
D000911:Antibodies, Monoclonal / Q000737:chemistry*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D002152:Calorimetry, Differential Scanning; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry; D007075:Immunoglobulin M / Q000737:chemistry*; D011489:Protein Denaturation; D013816:Thermodynamics
D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D007075:Immunoglobulin M