关键词：蛋白质；碳水化合物；生物分子；生物医学
摘 要：In this chapter, a detailed discussion on the salient features of structures of biomolecules like proteins, carbohydrates and nucleic acids is presented. Intermolecular interactions leading to phase separation, coacervation and nano-particle formation is discussed herein. Biomolecular solutions exist as gels, coacervates, dispersions and melts with each of these phases having its signature physico-chemical properties, which is discussed in this chapter. The discussions are supported by robust experimental data obtained from an array of methods like turbidimetry, elecrophoresis, viscosity, light scattering etc. The inevitability of the phenomenon of self-organization in biopolymers results in the generation of a variety of soft matter phases which do not, however, make it predictable. For instance, the associative aggregation is a process which remains obscure, as every protein aggregates in a different manner under different conditions. One known feature to the aggregation of proteins is the strong dependence upon pH, salt concentration and temperature. Beyond the influence of these factors and their effects on aggregation, the process is not well understood. An increase in protein usage in biomedical and pharmaceutical studies implicates protein aggregation in Alzheimer's, Parkinson's and other diseases, and have placed a growing importance upon understanding this behaviour in general. Comparison of the system to other protein-polyelectrolyte systems suggests that the preferential binding of the two could be a result of complexation of the two molecules which often lead to coacervation. Such association can even occur at pH greater than the isoelectric points (pI), when the net charge of protein is of the same sign as that of polyelectrolyte. Such binding though prevalent in nature is not well understood. In summary, a comprehensive account of biomolecular phase states and their inherent attributes are presented in this review.