A computer model of an AB copolymer with a membrane protein-type spatial structure

The conformational properties of an AB copolymer with the primary sequence of A and B units prepared on the basis of an analysis of the most general principles of the formation of the spatial structure of membrane proteins were studied by computer simulation. The sequence of copolymer units was constructed using the idea of so-called conformation-dependent synthesis; that is, monomeric units in a narrow central layer within a homopolymeric globule were assigned type A (hydrophobic), and the other units, type B (hydrophilic). A study of the coil-globule transition in such a copolymer chain revealed microsegregation (stratification) of hydrophilic units from different hemispheres on both sides of the narrow central layer in the "parent' conformation. The spatial structure of the parent globule was found to be, to a certain extent, inherited by the primary sequence of the AB copolymer. A statistical analysis of the AB sequence was performed and an explanation of the observed effect suggested.