Presclerotized eggshell protein from the liver fluke Fasciola hepatica.
Trematode parasites protect their eggs with a tough tanned eggshell. Eggshell precursor proteins are synthesized and stockpiled within the extensive vitellaria of the animal. A major eggshell precursor protein with an apparent molecular weight of 31,000 and pI of 7.4 was isolated from the vitellaria of Fasciola hepatica. This protein, which represents 6-7% of the total protein in mature Fasciola, is unique in containing rather high levels of the amino acid 3,4-dihydroxyphenylalanine (DOPA), i.e., 110 residues per 1000. Other prominent amino acids are glycine, aspartic acid, and lysine. A prominent DOPA-containing tryptic peptide derived from eggshell precursor protein has the sequence Gly-Gly-Gly-DOPA-Gly-Gly-DOPA-Gly-Lys. DOPA residues disappear during the maturation of the eggshell and by treatment in vitro with mushroom polyphenol oxidase. This disappearance may be related to the formation of cross-links in the eggshell protein.
Waite
J H
JH
College of Marine Studies, University of Delaware, Lewes 19958.
Rice-Ficht
A C
AC
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005210:Fasciola hepatica / Q000032:analysis*; D015801:Helminth Proteins; D008565:Membrane Proteins / Q000032:analysis* / Q000302:isolation & purification*; D008970:Molecular Weight; D014817:Vitelline Membrane / Q000032:analysis*
D000596:Amino Acids; D015801:Helminth Proteins; D008565:Membrane Proteins; C054857:presclerotized eggshell protein, Fasciola hepatica