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Characterization of Basic Proteins from Goldfish Myelin
Author(s) -
Mastronardi Fabrizio G.,
Boulias Chris,
Roots Betty I.,
Moscarello Mario A.
Publication year - 1993
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1993.tb05833.x
Subject(s) - myelin basic protein , polyclonal antibodies , biochemistry , epitope , myelin , neurofilament , amino acid , microbiology and biotechnology , antiserum , biology , protein a/g , chemistry , gene isoform , antibody , fusion protein , recombinant dna , immunohistochemistry , neuroscience , gene , immunology , central nervous system
Myelin basic protein (MBP) from common goldfish ( Carassius auratus ) myelin was extracted with dilute mineral acid. Immunological cross‐reactivity of the goldfish MBP, with polyclonal antisera raised against bovine MBP, suggested that the goldfish protein has epitopes for these antibodies. It also reacted with a monoclonal antibody specific for a seven amino acid epitope (130–137) conserved in the MBP of most mammalian species. To characterize the charge heterogeneity of this protein, we iodinated the protein with 125 I and chromatographed it on a carboxymethyl cellulose‐52 column together with a nonlabeled acid soluble fraction prepared from human white matter as a carrier protein. All of the goldfish protein was recovered in the unbound fraction, demonstrating that it was less cationic than the carrier protein (human MBP). We have also examined the urea alkaline gel profile of the goldfish MBP together with the human C‐1, C‐2, C‐3, C‐4, and C‐8 components. The results from these experiments indicated that this MBP extracted from goldfish brain myelin lacked the microhet‐erogeneity that is associated with MBPs from higher vertebrates. The MBPs from goldfish myelin were separated into their isoforms by reversed‐phase HPLC. Amino acid compositions were determined for both the 17‐ and 14‐kDa goldfish proteins. Amino acid analysis revealed similarities with the compositions of other MBPs; however, the serine content in both the 17‐ and 14‐kDa proteins was higher than that of the human C‐1, the mouse C‐1 protein, and the shark proteins. The HPLC‐purified 14‐kDa goldfish protein was chemically cleaved with CNBr for partial sequence analysis. Even from the limited sequence obtained, the sequence ATAST was found in goldfish, which is also present in human, rabbit, and guinea pig MBPs.