A comparative study on the bulk adhesive strength of the recombinant mussel adhesive protein fp-3

Mussel adhesive protein (MAP) type 3 (fp-3) is considered one of the key components for mussel adhesion. However, its bulk adhesive strength has not been characterized due to its availability in limited quantities. In the present work, a feasible production (~47 mg l(-1)) of recombinant fp-3 was achieved, and its bulk adhesive strength was measured for the first time; ~0.57 MPa for the unmodified form and ~0.94 and ~2.28 MPa for the 3,4-dihydroxy-L-phenylalanine (DOPA)-modified form, having a 9.6% yield without and with oxidant treatment, respectively. Furthermore, values for the bulk adhesive strength of several DOPA-modified recombinant MAPs were compared. The maximum adhesive strength of DOPA-modified fp-3 after oxidant treatment was stronger than that of type 5 (fp-5), which has a 6.2% modification yield, and was comparable to that of hybrid types fp-131 and fp-151, which have similar yields (~5%). The strong bulk adhesive property of recombinant fp-3 demonstrates its potential use as a promising bioadhesive.