Glycosylated hydroxytryptophan in a mussel adhesive protein from Perna viridis.
The 3,4-dihydroxyphenyl-l-alanine (Dopa)-containing proteins of mussel byssus play a critical role in wet adhesion and have inspired versatile new synthetic strategies for adhesives and coatings. Apparently, however, not all mussel adhesive proteins are beholden to Dopa chemistry. The cDNA-deduced sequence of Pvfp-1, a highly aromatic and redox active byssal coating protein in the green mussel Perna viridis, suggests that Dopa may be replaced by a post-translational modification of tryptophan. The N-terminal tryptophan-rich domain of Pvfp-1 contains 42 decapeptide repeats with the consensus sequences ATPKPW(1)TAW(2)K and APPPAW(1)TAW(2)K. A small collagen domain (18 Gly-X-Y repeats) is also present. Tandem mass spectrometry of isolated tryptic decapeptides has detected both C(2)-hexosylated tryptophan (W(1)) and C(2)-hexosylated hydroxytryptophan (W(2)), the latter of which is redox active. The UV absorbance spectrum of W(2) is consistent with 7-hydroxytryptophan, which represents an intriguing new theme for bioinspired opportunistic wet adhesion.
Zhao
Hua
H
Marine Sciences Institute, University of California at Santa Barbara, Santa Barbara, California 93106, USA.
Sagert
Jason
J
Hwang
Dong Soo
DS
Waite
J Herbert
JH
D006916:5-Hydroxytryptophan / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D016384:Consensus Sequence; D006031:Glycosylation; D008969:Molecular Sequence Data; D049883:Perna / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
D011506:Proteins; C037403:adhesive protein, mussel; D006916:5-Hydroxytryptophan