Intermacromolecular interactions

Even in macromolecular systems, the secondary binding forces mentioned up to here act in the same manner as in the case of low molecular weight compounds, if one considers secondary bonds individually. However, for all practical purposes, they act at the same time in an extremely complicated manner, concertedly and never separately. Moreover, each active site of the molecule interacts cooperatively with other sites because of the neighboring effect (for details see Sect. 4). Therefore, in intra- and intermacromolecular interaction systems, it is quite difficult to investigate separately the effective secondary binding forces, and it should be noted that the total interaction force might not be the sum of the individual binding forces. 

Many molecules including biopolymers participate in biological functions as a molecular assembly or tissue the self-assembly of the microtublin of bacterial flagella, antigen-antibody reactions, the high activity and selectivity of enzymes, etc. are skillfully and accurately achieved by intermacromolecular interactions. 

Studies on the interaction between oppositely charged polyelectrolytes date back to 1896 when Kossel389 precipitated egg albumin with protamine. Since that time extensive studies have been made on pairs of strong polyelectrolytes, pairs of strong and weak polyelectrolytes, pairs of weak polyelectrolytes, as well as on amphoteric complexes. However, the theoretical considerations of intermacromolecular interactions between polyelectrolytes were only based on extremely simplified model systems. However, even in the case of such systems, there are many unsolved problems such as the determination of the local dielectric constant in domains of macromolecular chains, the evaluation of other secondary binding forces, especially hydrophobic interactions, and so on. 

Other applications of intermacromolecular interaction and complexes are picked up as follows. Some water-soluble nonionic polymers have been applied to the isolation of some serum proteins from human serum under mild conditions different from former techniques such as Cohn method579 and... 

High sensitivity of the IMM of the polymer to changes in intramacromolecular interactions of various types (specific or Van der Waals interactions, etc.) permits to make use of the relaxation properties of the polymer for studying intermacromolecular interactions in polymer-polymer complexes (PC). A comparative investigation of the IMM of macromolecules constituting PC and single macromolecules of each of its components has been carried out for a number of PC 3i-i33) nKthod... 

The effect of intermacromolecular interactions on the IMM of the polymer chains forming PC has been investigated in detail for PMAA-PEG complexes. Data... 

G. D. J. Phillies. Effects of intermacromolecular interactions on diffusion. II. Three-component solutions. J. Chem. Phys., 60 (1974), 983-989. 

Dielectric relaxation thus resembles self-diffusion. Both processes observe the motion of single macromolecules through a uniform albeit fluctuating background. In a two-component polymer-solvent system, dielectric spectroscopy reveals the effect of intermacromolecular interactions on single-molecule size and reorientation. Dielectric measurements on a three-component polymer-polymer-solvent mixture, in which a tracer polymer has a nonzero type-A dipole and a potentially nondilute matrix polymer has none, can be used for example to separate the effects of probe and matrix molecular weights on dielectric relaxation. This motif in the comparative study of binary and ternary solutions appears repeatedly below. Finally, dielectric measurements on block copolymers in which some copolymer subchains have been inverted end-to-end or have no dipole moment allow one to observe internal motions and dynamic cross-correlations of subchains. 

Whatever the type of interaction, one has to bear in mind that the energy produced by van der Waals interactions scales with r , which explains that both intra- and intermacromolecular interactions contribute to the cohesion of polymeric systems. 

In the contrast to native BSA sample, intermacromolecular interaction of the BSA sample with gelatin leads to formation of the laige complex particles of the BSA associates with gelatin, the partial unfolding globular protein and formation of the charged complex particles. 

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