A structural comparison of type c lysozymes based on their hydropathic profiles.
Hydropathic profiles can be considered as an approach to the three-dimensional structure of a protein and so their use for comparison of homologous proteins is proposed, as they provide information on relative structural conservativeness. A simple approach was developed for comparison of hydropathic profiles and applied to 19 lysozymes c of known primary structure. Trees were constructed in order to discover which method yielded the best estimation of the phenotypic differences between the proteins considered, by means of the goodness-of-fit criterion. Iterative methods, such as the Fitch-and-Margoliash and the unweighted-pair-group methods, gave a better fit than did a non-iterative method. When the hydropathic approach is used for comparison of lysozymes c, the enzyme obtained from chachalaca egg-white is placed closer to those from pheasant-like birds than to those of ducks; this result agrees with the morphological resemblance of the chachalaca to pheasant-like birds. Pigeon egg-white and equine milk lysozymes differ greatly in sequence from other lysozymes c and their hydropathic analysis shows important differences with respect to the other homologous enzymes.
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad Complutense, Madrid, Spain.
L
L
Menéndez-Arias
J G
JG
Gavilanes
R
R
Rodriguez
D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D009113:Muramidase; D009154:Mutation; D010802:Phylogeny; D011487:Protein Conformation
D009113:Muramidase