The TCV coat protein dimer (shown in the diagram below) has N-terminal tails, that are very sensitive to protease digestion when exposed. So when the virus is digested with chymotrypsin, they are cleaved off.
Chymotrypsin is a serine endopeptidase, that becomes active after cleavage with another protease trypsin; this enzyme cleaves between the arginine and isoleucine (R15 and L16), causing structural modification and formation of the substrate binding site. Chymotrypsin selectively cleaves peptide bonds formed by aromatic residues (eg. tyrosine, phenylalanine), as it prefers to cleave at large hydrophobic residues.