title: Endothelin-3-converting enzyme activity of the KEL1 and KEL6 phenotypes of the Kell blood group system.
abstract: The Kell blood group protein is a metalloendopeptidase that preferentially cleaves a Trp(21)-Ile(22) bond of big endothelin-3 producing bioactive endothelin-3. Kell is a polymorphic protein, and 25 different phenotypes, because of point mutations resulting in single amino acid substitutions, have been described. It was recently reported that a recombinant form of KEL1 (K, K1) phenotype, expressed in K562 and HEK293 cells, had no endothelin-3-converting activity, in contrast to the common KEL2 (k, K2) phenotype. We demonstrate that KEL1 red blood cells and also a soluble recombinant form of KEL1 protein (s-Kell KEL1) have similar enzymatic activity as the common Kell phenotype. In addition we show that KEL6 red blood cells, which are more prevalent in persons of African heritage than in Caucasians also have endothelin-3-converting enzyme activity and that the recombinant soluble form of KEL6 protein (s-Kell KEL6) has similar K(m) values as the wild-type.
authors.affiliation: Lindsley F. Kimball Research Institute of the New York Blood Center, 310 East 67th Street, New York, NY 10021, USA.
authors.forename: Quan
authors.initials: Q
authors.lastname: Sha
authors.forename: Colvin M
authors.initials: CM
authors.lastname: Redman
authors.forename: Soohee
authors.initials: S
authors.lastname: Lee
mesh_terms: D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002384:Catalysis; D002460:Cell Line; D002846:Chromatography, Affinity; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D000072396:Endothelin-Converting Enzymes; D004912:Erythrocytes; D006801:Humans; D007313:Insecta; D007532:Isoleucine / Q000737:chemistry; D007626:Kell Blood-Group System; D007700:Kinetics; D008666:Metalloendopeptidases / Q000737:chemistry* / Q000378:metabolism; D017830:Octoxynol / Q000737:chemistry; D010641:Phenotype; D017354:Point Mutation; D011110:Polymorphism, Genetic; D011994:Recombinant Proteins / Q000737:chemistry; D014364:Tryptophan / Q000737:chemistry
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D007626:Kell Blood-Group System; D011994:Recombinant Proteins; D007532:Isoleucine; D014364:Tryptophan; D017830:Octoxynol; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D000072396:Endothelin-Converting Enzymes