Evidence from sequence analysis that hen egg-white ovomacroglobulin (ovostatin) is devoid of an internal beta-Cys-gamma-Glu thiol ester.
53 residues of the internal sequence from the proteinase-binding hen egg-white ovostatin have been determined. The stretch corresponds to residues 945-997 of human alpha 2-macroglobulin. The degree of conservation of residues of the two stretches is approx. 74%. Cys-949, being one constituent of the internal thiol ester site of members of the family of proteins related to alpha 2-macroglobulin, is an Asn-residue in hen egg-white ovostatin, but the other constituent, Gln-952, is preserved. The Cys-to-Asn substitution forms the chemical basis for the lack of thiol esters in hen egg-white ovostatin.
Nielsen
K L
KL
Department of Molecular Biology, University of Arhus, Denmark.
Sottrup-Jensen
L
L
D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004529:Egg White / Q000032:analysis*; D004952:Esters / Q000032:analysis*; D006801:Humans; D008259:Macroglobulins / Q000737:chemistry*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013438:Sulfhydryl Compounds / Q000032:analysis*; D000511:alpha-Macroglobulins / Q000737:chemistry*
D004952:Esters; D008259:Macroglobulins; D013438:Sulfhydryl Compounds; D000511:alpha-Macroglobulins; C036828:ovomacroglobulin