Temperature-dependent isologous Fab-Fab interaction that mediates cryocrystallization of a monoclonal immunoglobulin G.
Mechanisms of the cryoprecipitation of cryoglobulins have long been studied but not fully understood. In the present study, we characterize a monoclonal immunoglobulin G1 (IgG1) cryoglobulin that forms sharp needle crystals upon cooling and therefore might be an ideal example for the elucidation of a mechanism of cryoprecipitation of cryoglobulins. Limited proteolysis by papain of this cryoglobulin resulted in disappearance of cryocrystallization. Interactions of the proteolytic fragments were examined by surface plasmon resonance measurements. A temperature-dependent isologous Fab-Fab interaction was observed for this cryoglobulin. Glycosylation profiling by use of the HPLC mapping technique revealed that cryoglobulin expresses homogeneous N-glycans in its Fc portion. These results suggest that (1) the temperature-dependent crystallization of the cryoglobulin was ascribed to its specific Fab-Fab interaction and (2) the unusual homogeneity of the Fc glycosylation promote the crystallization of this cryoglobulin.
Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan.
Hirokazu
H
Yagi
Noriko
N
Takahashi
Yoshiki
Y
Yamaguchi
Koichi
K
Kato
D003450:Cryoglobulins / Q000737:chemistry*; D003460:Crystallization; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry*; D011485:Protein Binding; D020349:Surface Plasmon Resonance; D013696:Temperature
D003450:Cryoglobulins; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G