title: Amino acid sequence and immunological properties of chalchalaca egg white lysozyme.
abstract: The amino acid sequence of lysozyme c from chachalaca egg white was determined. Like other bird lysozymes c, that of the chachalaca has 129 amino acid residues. It differs from other avian lysozymes c by 2 to 31 amino acid substitutions as well as by being devoid of phenylalanine. It contains substitutions at 9 positions which are invariant in the other 7 bird lysozymes of known sequence. Although the chachalaca is classified zoologically in the order Galliformes, which includes chickens and other pheasant-like birds, its lysozyme differs more from those of pheasant-like birds than do the lysozymes c of ducks. Phylogenetic analysis of the sequence comparisons confirms that the lineage leading to chachalaca lysozyme c separated from that leading to other galliform lysozymes c before the duck lysozyme c lineage did. This indicates a contrast between protein evolution and evolution at the organismal level. Immunological comparison of chachalaca lysozyme c with other lysozymes of known sequence provides further support for the proposal that immunological cross-reactivity is strongly dependent on degree of sequence resemblance among bird lysozymes.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001717:Birds / Q000378:metabolism*; D003429:Cross Reactions; D004529:Egg White / Q000032:analysis*; D009113:Muramidase / Q000032:analysis* / Q000276:immunology; D010446:Peptide Fragments / Q000032:analysis; D010802:Phylogeny; D013045:Species Specificity; D014357:Trypsin
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D009113:Muramidase; D014357:Trypsin