Vol 48(2014) N 3 p. 414-423; DOI 10.1134/S0026893314030200
Relations between Macro- and Microstability of СН2 Domains and Human IgG2 and Their Biological Activity: 1. Analysis of Calorimetric and Optical Melting CurvesInstitute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
Received - 2013-10-17; Accepted - 2013-11-25
In this study, we examined the human myeloma second-class immunoglobulins, LOM and SIN, and their Fc fragments, by a number of physical methods, such as scanning calorimetry, fluorescence spectroscopy and analytical centrifugation. In addition, we obtained and carried out a separate analysis of their hFc fragments, which contain not only the lower portion of the hinge region, but its complete core peptide, Cys-Cys-Val-Glu-Cys-Pro-Pro-Cys. Joint analysis of calorimetric and optical melting curves revealed that only the first low-temperature heat absorption peak in all of the melting curves corresponded to the melting of the two СН2 domains. Thus, we demonstrate that the СН2 domains of the intact IgG2 are present in a less compact conformation compared to their state within the hFc and Fc fragments.
immunoglobulin IgG2, Fc and hFc fragments, СН2 domain, thermostability