GFP Adeno-Associated Virus ( AAV-GNEVL )

The VP3 capsid protein subunit of AAV consists of eight antiparallel β-strands forming a barrel-like structure. The β-strands are interconnected by variable loops, which are located on the capsid surface. VP1, VP2, and VP3 monomers assemble through two-, three-, and five-fold symmetry axes to form the 60-subunit AAV capsid. The two-fold symmetry axes are characterized by depressions, where the variable loops form barriers between these depressions. The staggered variable loops form specific surface topologies at different symmetry axes that are unique to each AAV isolate. In addition to determining capsid-glycan interactions, the variable loops play a crucial role in determining antigenicity and other secondary interactions that may be involved in cell entry or post-entry trafficking events. The heparan sulfate (HS) recognition motif on the AAV serotype 2 capsid was the first glycan receptor footprint to be identified in the AAV family. Mutational analysis of a series of basic residues (R484, R487, R585, R588, and K532) located within the spike surface of the triple-axle spike revealed that these residues are critical for HS binding. GFP AAV-GNEVL particles contain an engineered capsid derived from AAV serotype 2 (AAV2) that features an insertion of the peptide sequence GNEVLGTKPRAP at position I588. The primary target cell type for this engineered AAV capsid is cardiomyocytes, which are progenitor cells that can differentiate into cardiomyocytes (cells that make up heart muscle tissue). This specificity makes GFP AAV-GNEVL a valuable tool for cardiovascular research, particularly in understanding cardiac development, disease mechanisms, and potential therapeutic interventions.