An Unusual Sialoglycoprotein Associated with the Webb‐Positive Phenotype

This paper describes the association of the low-frequency antigen Lsa with high-molecular-weight variants of β- and γ-sialoglycoproteins (β-SGP, γ-SGP). The variant β-SGP, designated β^Ls^a, carries the Ge^3 epitope and the epitopes recognised by 3 murine monoclonal anti-β-SGP antibodies. The variant γ-SGP, designated γ^Ls^a, carries the Ge^2 and Ge^3 epitopes. Both β^Ls^a and y^Ls^a showed enhanced reactions in immunoblotting with anti-Ge3 sera - which may indicate the presence of 2 Ge3 epitopes on β^Ls^a and γ^Ls^a These findings would be consistent with the proposed structure of the Ls^a glycophorin C gene.

Section: Discussionsupporting

confidence: 81%

“…Gels were stained with either PAS, Coomassie blue or silver. Tritiated erythrocyte membrane proteins were visualised using autofluorography [11].…”

Section: Methods and Family Historymentioning

confidence: 99%

Abnormal Beta and Gamma Sialoglycoprotein Associated with the Low-Frequency Antigen Ls

Macdonald¹,

Condon²,

Ford³

et al. 1990

“…Such an interaction was first proposed by Mueller and Morrison [83], and was based on the observation that Glycophorin C, which is a normal constituent of red cell skeleton preparations, was not found in red cell skeletons prepared from an individual with hereditary elliptocytosis who had a total deficency of band 4.1. Subsequently, Anstee et al [81] 90], Individuals whose red cells have the low frequency anti gen Wb have an abnormal form of Glycophorin C which appears to result from the absence of the N-glycan at Asn8 [91,92], Remarkably, red cells from both the Gerbich type of Gerbich negative [86,93], and of the Leach phenotype [87] show weakened expression of Kell antigens, especially K:ll. This weakening can also be demonstrated when mu rine monoclonal Kell antibodies are used [94].…”

Section: Gerbich Antigensmentioning

confidence: 99%

Blood Group-Active Surface Molecules of the Human Red Blood Cell

Anstee¹

1990

The surface of the human red blood cell is dominated by a small number of abundant blood group active proteins. The major proteins are the anion transport protein (band 3) which has AB(H) activity, and Glycophorin A which has MN activity. Band 3 and Glycophorin A are of equal abundance in the normal red cell membrane (approximately 10^6 copies of each) and the two proteins may associate together as a complex. The glucose transporter (band 4.5) has AB(H) activity and there are about 5 x 10^5 copies/red cell. Several polypeptides associate together to form the Rh complex. The major components of this complex (abundance 1-2 x 10^5 copies/red cell) are polypeptides of M(r) 30,000, polypeptides of M(r) 45,000-100,000 and Glycophorin B. The antigens of the Rh blood group system appear to be associated with the polypeptides of M(r) 30,000 and those of M(r) 45,000-100,000 (the latter also express AB(H) activity). Glycophorin B expresses the blood group ‘N’ antigen and the Ss antigens. Glycophorins C and D carry the Gerbich antigens and, together, these polypeptides comprise approximately 10^5 copies/red cell. The complete protein sequence of all the above-mentioned proteins is known, except for the M(r) 30,000 and M(r) 45,000-100,000 polypeptides of the Rh complex for which only partial sequences are available, and Glycophorin D, the sequence of which can be inferred from that of Glycophorin C. Several of the minor blood group active proteins at the red cell surface (abundance <1.2 x 10^4 /red cell) have been the subject of recent studies. The polypeptide expressing Cromer-related blood group antigens has been identified as decay-accelerating factor and that carrying the In^a / In^b antigens as CD44. The protein sequence of both of these proteins has been deduced form nucleotide sequencing. The polypeptides expressing Kell antigens, Lutheran antigens, Fy antigens, and LW antigens have also been identified and partially characterised.

“…Serum haptoglobin was typed by the method of Smithies [7] using the buffer system of Poulik [8], Gm and Km allotypes were established using a standard 3-drop haemagglutination inhibition assay as described by Propert [9]. DNA was extracted from peripheral blood lymphocytes by the method of Sambrook et al [10], RFLP analysis was performed according to Zelinski [11], SDS-PAGE was carried out after the method of Laemmli [12] followed by immunoblotting utilizing the methods of Merry et al [13] and Mac donald and Gems [14], Red cells were treated with 2-amino-ethylisothtouronium bromide ( AET) after the method of Advani et al [15]. …”

Section: Methodsmentioning

confidence: 99%

A New Low-Frequency Red Cell Antigen, 'SARAH'

Stern¹,

Hawksworth²,

Watt³

et al. 1994

There are more than 100 low-frequency antigens (LFAs) which have been given International Society of Blood Transfusion (ISBT) numbers as members of systems, collections or the 700 series. In addition, there are a number of well-known (to reference laboratories) unpublished LFAs. The presence of an LFA was suspected when 2 sera were found to react with a single example of K homozygous cells. Anti-K reacting with K homozygotes was eliminated on testing with other KK cells. Testing of the reactive cell with antibodies to known LFAs and the reactive sera with cells known to carry LFAs failed to identify the specificity. A study on the family of the cell donor showed inheritance of the antigen in two generations. Further testing, which included immunoblotting and RFLPs, was carried out in Australia, the UK, Canada and the USA. By March 1993 all published LFAs had been excluded, and an application was made to the ISBT to have the antigen, SARAF1, assigned a 700 series number. In April the number 700.052 was provisionally designated for this new antigen.