Presentation day

Tuesday  4:40 PM

 

TITLE

Solution self-assembly of protein-polymer conjugate

 

Abstract

Protein-polymer covalent conjugates are being developed for applications such as
targeted drug delivery, protein therapeutics and enhanced cellular delivery of drugs crossing the bloodbrain
barrier. The conjugates may exist as single molecules or they can self-assemble to create
multimolecular micelle structures. The polymer in the conjugate can be hydrophobic, hydrophilic or
amphiphilic. The protein provides hydrophilicity and hydrophobicity depending on the charge and polarity
characteristics. The self-assembly behavior is thus controlled by both the polymer and protein molecular
properties. We develop a simple phenomenological treatment of protein-polymer conjugate micelles
considering various molecular properties for the polymer and the protein. Different structural descriptions
for the self-assembled aggregates are postulated and quantitative models for free energy change on
forming such self-assembled structures are constructed. These free energy expressions build upon the
type of free energy models we have constructed earlier for polymeric amphiphiles and now take into
account the protein dependent free energy contributions. From the free energy minimization of the system,
we calculate the critical concentration of the conjugates for micelle formation and the structure and size of
the self-assembled aggregates. We identify the essential physicochemical features of the polymer and the
protein necessary for the conjugates to self-assemble into various structural motifs.