title: Cement precursor proteins of the reef-building polychaete Phragmatopoma californica (Fewkes).
abstract: Two distinctive 3,4-dihydroxyphenyl-L-alanine-(DOPA-) containing proteins (Pc-1 and Pc-2) have been isolated and partially characterized from the thorax of the reef-building sabellariid Phragmatopoma californica. They are the first such reported from the phylum Annelida. The proteins are presumed to be soluble precursors of the quinone-tanned cement used to bind particulate materials in the construction of the tubes that serve as habitats for the worms. The proteins have apparent molecular weights ranging from 18,000 to 20,000 and isoelectric point greater than or equal to 8.0. Both proteins consist of repeated sequence motifs in their primary structure. Pc-1 has repeats of (XGGY*GY*GAK) where X = V, L, I, AA, or KV, and Y* is DOPA or tyrosine. Pc-2, in contrast, appears to have repeats of (X1-[GGY*]n-[GA]m-X2-[HP(A)V]p-HK) where X1 can be AL, A, or F; X2 can be WG or absent; n and m can be 1 or 2, and p = 0-2. Both protein families appear to share the same C-terminal sequence ALGGY*GAGA. Of the DOPA-containing proteins characterized from other phyla, Phragmatopoma cement precursors most resemble those from the liver fluke Fasciola hepatica and the mussel Trichomya hirsuta.
authors.affiliation: College of Marine Studies, University of Delaware, Lewes 19958.
authors.forename: J H
authors.initials: JH
authors.lastname: Waite
authors.forename: R A
authors.initials: RA
authors.lastname: Jensen
authors.forename: D E
authors.initials: DE
authors.lastname: Morse
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004295:Dihydroxyphenylalanine / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007447:Invertebrate Hormones / Q000737:chemistry*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011077:Polychaeta / Q000737:chemistry*; D011498:Protein Precursors / Q000737:chemistry*; D012091:Repetitive Sequences, Nucleic Acid; D014357:Trypsin / Q000378:metabolism
chemical_list: D007447:Invertebrate Hormones; D010446:Peptide Fragments; D011498:Protein Precursors; D004295:Dihydroxyphenylalanine; D014357:Trypsin