No abstract

The N-terminal structures of the MN and Ss erythrocyte membrane sialoglycoproteins (glycophorins A, B) from two Henshaw (He) blood-group heterozygotes were determined by manual sequencing of tryptic glycopeptides and various secondary fragments. No structural alteration of the M N glycoprotein co+uld be de+tected. The He-specific portion of the Ss glycoprotein was found to exhibit the N-terminal sequence Trp-Ser-Thr-Ser-Gly-(+ = glycosylation). Thus it differs at three positions from its normal counterpart which possesses 'N' activity and exhibits the N-terminal structure Leu-Sir-Thr-Thr-Glu-. Analysis of the Ss glycoprotein from 15 He-negative erythrocyte samples did not reveal any of the three He-specific structural alterations. The presence of a glycine residue at the fifth position of the blood-group-M-active M N glycoprotein as well as in the He-specific Ss glycoprotein provides an explanation for the occurence of antisera (anti-Me) reacting with the M and He antigens. + +Previous studies have provided evidence that the human MN and Ss blood-group gene loci encode the amino acid sequences of two (MN and Ss) sialoglycoproteins (SGPs) (synonyms : glycophorins A, B) in red blood cell membranes [I -41. Amino acid polymorphisms at the first (serinejleucine) and fifth (glycine/glutamic acid) positions of the major (MN) SGP determine M N blood-group specificity [5 -101, whereas the Ss antigens appear to be dependent on a methioninel threonine polymorphism at position 29 of the Ss SGP [ l l -131. The N-terminal 26 residues of the Ss SGP are identical with those of the blood-group-N-active major glycoprotein [9 -121. Therefore, the former molecule carries an additional N receptor, denoted as 'N' [1,3].The Henshaw (He) erythrocyte antigen, which occurs in about 5% of blacks and only rather rarely in Caucasians, is genetically associated with the MNSs receptors [ l , 14 -171. Serological studies have revealed that certain rabbit or human antisera, denoted as anti-Me, react with the He and M antigens, suggesting that both receptors exhibit a structural similarity. In the present communication we describe studies on the SGPs from two He heterozygotes. Our data demAbbreviations. BNPS-skatole, 2-(2-nitrophenylsulfenyl)-3-methyl-3-bromoindolenine; dansyl-, l-(dimethylamino)naphthalene-5-sulphonyl-; DABITC, 4-N,N-dimethylaminoazobenzene-4'-isothiocyanate; DABTH, 4-N,N-dimethylaminoazobenzene-4'-thiohydantoin; PITC, phenylisothiocyanate; SGP, sialoglycoprotein. Peptides are designated according to the SGP (MN or Ss) from which they were derived by trypsin (T), chymotrypsin (C), V8 protease (V) (after desialylation (d)) or cyanogen bromide (B) treatment, the elution during gel filtration (1 etc.) (EC 3.4.21.19). [3,7 -9,31,12,18 -221. Analytical proceduresSialic acid, protein and sodium dodecylsulfate/polyacrylamide gel electrophoretic analyses were performed by the methods of Warren [23], Lowry et al. [24] and Laemmli [22,25], respectively. Amino acids and amino sugars were determined on automated amino acid analyzers [...

The TERS appears to be a reliable and valid measure with clinical utility for specifying behavioral concerns prior to lung transplantation.

26 patients with an acute reversible ITP and 6 with chronic ITP were tissue typed, together with their healthy first-degree relatives. The HLA frequencies of the different groups were compared with those of a normal control population. The only significant difference between the groups was an increase in the frequency of Aw32 in acute ITP patients. HLA-Aw32 was present in 26.9% of patients, but in only 0.8% of the controls (corrected P = 0.000027). The possible importance of associations between antigens of the HLA-A locus with certain diseases are discussed. Family analyses and haplotype determinations proved to be unproductive because no familial clustering of ITP was found.