Aggregation kinetics and structure of cryoimmunoglobulins clusters

• Published in: PHYS A STAT MECH APPL Vol. 304; no. 1; pp. 211 - 219
• Main Authors: Spirito, M.De, Chiappini, R, Bassi, F.Andreasi, Stasio, E.Di, Giardina, B, Arcovito, G
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Elsevier B.V 01-02-2002
• Subjects: Agglomeration; Antigens; Bonding; Chemical bonds; Configuration; Conformation; Conformations; Disperse systems; Isomerism of biomolecules; Light scattering; Macromolecules; Molecular structure; Physical chemistry of solutions of biological macromolecules; Precipitation (chemical); Reaction kinetics; Structure; Thermal effects; 87.15.By; 82.70.−y; Disperse systems; Configuration; 87.15.Da; Structure; Bonding; Physical chemistry of solutions of biological macromolecules; Isomerism of biomolecules; Conformation
• ISSN: 0378-4371; 1873-2119
• DOI: 10.1016/S0378-4371(01)00538-6

Cryoimmunoglobulins are pathological antibodies characterized by a temperature-dependent reversible insolubility. Rheumatoid factors (RF) are immunoglobulins possessing anti-immunoglobulin activity and usually consist of an IgM antibody that recognizes IgG as antigen. These proteins are present in sera of patients affected by a large variety of different pathologies, such as HCV infection, neoplastic and autoimmune diseases. Aggregation and precipitation of cryoimmunoglobulins, leading to vasculiti, are physical phenomena behind such pathologies. A deep knowledge of the physico-chemical mechanisms regulating such phenomena plays a fundamental role in biological and clinical applications.
In this work, a preliminary investigation of the aggregation kinetics and of the final macromolecular structure of the aggregates is presented. Through static light scattering techniques, the gyration radius
R
g and the fractal dimension
D
m of the growing clusters have been determined. However, while the initial aggregation mechanism could be described using the universal reaction-limited cluster–cluster aggregation (RLCCA) theory, at longest times from the beginning of the process, the RLCCA theory fails and a restructuring of clusters is observed together with an increase of the cluster fractal dimension
D
m up to a value
D
m∼3. The time
t
n, at which the restructuring takes place, and the final cluster size can be modulated by varying the quenching temperature.