title: Amino acid sequence around the thiolester of alpha 2-macroglobulin from plasma of the crayfish, Pacifastacus leniusculus.
abstract: Alpha 2-Macroglobulin (alpha 2 M) was isolated from plasma of the freshwater crayfish, Pacifastacus leniusculus, using ultracentrifugation, ion-exchange chromatography and gel filtration techniques. The Pacifastacus alpha 2 M molecule (P alpha 2 M) was radio-actively labeled in the thiol ester structure with iodo [14C]acetic acid in the presence of methylamine. After reduction and carboxymethylation of the protein, it was digested with trypsin. A 14C-labeled tryptic peptide was sequenced and contained an amino acid sequence very similar to other known thiol ester sequences from human alpha 2 M and related proteins. The N-terminal sequence of P alpha 2 M was related to that recently determined for lobster alpha 2 M [(1987) J. Biol. Chem. 262, 14606-14611].
authors: Department of Physiological Botany, University of Uppsala, Sweden.
authors: M
authors: M
authors: Hall
authors: K
authors: K
authors: Söderhäll
authors: L
authors: L
authors: Sottrup-Jensen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003400:Astacoidea / Q000378:metabolism*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D006458:Hemolymph / Q000032:analysis*; D006801:Humans; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis; D011480:Protease Inhibitors / Q000302:isolation & purification; D014357:Trypsin; D014461:Ultracentrifugation; D000511:alpha-Macroglobulins / Q000302:isolation & purification*
chemical_list: D010446:Peptide Fragments; D011480:Protease Inhibitors; D000511:alpha-Macroglobulins; D014357:Trypsin