Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
Individuals of the rare "Bombay" ( o h ) blood-group phenotype are lacking, due to a genetic defect, the a( 1 -2)fucosyl transferase, which is responsible for converting blood-group H precursor substances to H-specific structures. Treatment with GDP-fucose and a( 1 -2)fucosyl transferase prepared from gastric mucosa of 0 individuals failed to transform native or ficin-treated "Bombay" erythrocytes into cells phenotypically resembling 0 cells. The transformation was achieved, however, after prior incubation of the "Bombay" erythrocytes with neuraminidase, indicating that bloodgroup H precursor molecules on the surface of these cells are masked by sialyl residues. Bloodgroup A specificity was conferred upon neuraminidase-treated "Bombay" cells by enzymatic transfer of a-N-acetylgalactosamine residues, in addition to a-fucose residues.The rare "Bombay" ( o h ) phenotype is characterized by the absence of any A, B or H blood-group specificity from red cells and secretions 111. Persons belonging to this phenotype are believed to be homozygous for the gene h, whose active allele H codes for an a(1-2)fucosyl transferase, which converts blood-group H precursor substances to H-specific structures [2]. Since H substances are in turn the essential precursors of A and B substances [2 -41, red cells and secretions of "Bombay" individuals fail to exhibit A and B, as well as H specificities. Indeed, investigations on the occurrence in serum of a( 1 -2)-fucosyl transferase showed that this enzyme, which is present in all normal ABO donors, irrespective of their secretor status, is missing in "Bombay" individuals [5,6].Recently we were able to show that 0 erythrocytes were transformed to blood-group A and B specific cells when incubated with a-N-acetylgalactosaminyl and a-galactosyl transferases in the presence of the appropriate sugar nucleotides 171. The change of the serological specificities of the cell-bound blood-group substances was assessed by agglutination with and absorption of specific antisera. In this communication experiments are described which led to the conversion of "Bombay" erythrocytes to 0 (H) specific cells by transfer of a(1-2)fucose residues with the aid of a(1-2)fucosyl transferase. Red cell stromata were prepared by lysis of erythrocytes in distilled water. The erythrocyte ghosts were lyophilized after washing them three times with distilled water, twice with saline and again twice with distilled water. MATERIALS AND METHODS BloodDesialization of erythrocytes was effected by incubation of 0.5 ml of packed red cells in 5 ml of 0.145 M NaCl/10 mM Tris-C1 (pH 7.2) containing 50 I.U. of neuraminidase (V. cholerae, Behringwerke, Marburg/Lahn) for 30 min at 37 "C. After incubation the cells were washed three times with saline in order to remove the enzyme. Likewise, 50 mg of lyophilized stromata were treated with 2 ml of the neuraminidase solution for 2 h at 37 "C. After washing three times with distilled water, the enzyme-treated stromata were lyophilized.Ficin treatment of the red cells was performed as de...
Individuals of the rare "Bombay" ( o h ) blood-group phenotype are lacking, due to a genetic defect, the a( 1 -2)fucosyl transferase, which is responsible for converting blood-group H precursor substances to H-specific structures. Treatment with GDP-fucose and a( 1 -2)fucosyl transferase prepared from gastric mucosa of 0 individuals failed to transform native or ficin-treated "Bombay" erythrocytes into cells phenotypically resembling 0 cells. The transformation was achieved, however, after prior incubation of the "Bombay" erythrocytes with neuraminidase, indicating that bloodgroup H precursor molecules on the surface of these cells are masked by sialyl residues. Bloodgroup A specificity was conferred upon neuraminidase-treated "Bombay" cells by enzymatic transfer of a-N-acetylgalactosamine residues, in addition to a-fucose residues.The rare "Bombay" ( o h ) phenotype is characterized by the absence of any A, B or H blood-group specificity from red cells and secretions 111. Persons belonging to this phenotype are believed to be homozygous for the gene h, whose active allele H codes for an a(1-2)fucosyl transferase, which converts blood-group H precursor substances to H-specific structures [2]. Since H substances are in turn the essential precursors of A and B substances [2 -41, red cells and secretions of "Bombay" individuals fail to exhibit A and B, as well as H specificities. Indeed, investigations on the occurrence in serum of a( 1 -2)-fucosyl transferase showed that this enzyme, which is present in all normal ABO donors, irrespective of their secretor status, is missing in "Bombay" individuals [5,6].Recently we were able to show that 0 erythrocytes were transformed to blood-group A and B specific cells when incubated with a-N-acetylgalactosaminyl and a-galactosyl transferases in the presence of the appropriate sugar nucleotides 171. The change of the serological specificities of the cell-bound blood-group substances was assessed by agglutination with and absorption of specific antisera. In this communication experiments are described which led to the conversion of "Bombay" erythrocytes to 0 (H) specific cells by transfer of a(1-2)fucose residues with the aid of a(1-2)fucosyl transferase. Red cell stromata were prepared by lysis of erythrocytes in distilled water. The erythrocyte ghosts were lyophilized after washing them three times with distilled water, twice with saline and again twice with distilled water. MATERIALS AND METHODS BloodDesialization of erythrocytes was effected by incubation of 0.5 ml of packed red cells in 5 ml of 0.145 M NaCl/10 mM Tris-C1 (pH 7.2) containing 50 I.U. of neuraminidase (V. cholerae, Behringwerke, Marburg/Lahn) for 30 min at 37 "C. After incubation the cells were washed three times with saline in order to remove the enzyme. Likewise, 50 mg of lyophilized stromata were treated with 2 ml of the neuraminidase solution for 2 h at 37 "C. After washing three times with distilled water, the enzyme-treated stromata were lyophilized.Ficin treatment of the red cells was performed as de...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.