The primary structure of donkey (Equus asinus) lysozyme contains the Ca(II) binding site of alpha-lactalbumin.
The complete primary structure of donkey lysozyme has been established by pulsed liquid-phase sequencing of tryptic and chymotryptic peptides isolated by RP-HPLC. The positions of the Cys residues were identified by labeling the Cys residues with DABIA-reagent. Donkey lysozyme is a c-type lysozyme which is 129 amino acids long. It exhibits 50% homology to the human protein. We observe the full Ca(II) binding site suggested for the homologous alpha-lactalbumines. Although horse lysozyme has been reported to contain asparagine in position 61, which was in conflict with the three-dimensional structure of lysozyme, all other known c-type lysozymes, including donkey, contain Ser 61.
Godovac-Zimmermann
J
J
Division of Biochemical Sciences, John Curtin School of Medical Research, Australian National University, Canberra.
Conti
A
A
Napolitano
L
L
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D002918:Chymotrypsin; D006736:Horses; D007768:Lactalbumin / Q000378:metabolism*; D008969:Molecular Sequence Data; D009113:Muramidase / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D014357:Trypsin
D010446:Peptide Fragments; D007768:Lactalbumin; D009113:Muramidase; D002918:Chymotrypsin; D014357:Trypsin; D002118:Calcium