T. Miyaji

Hemoglobin Hiroshima (β143 histidine → aspartic acid): a newly identified fast moving beta chain variant associated with increased oxygen affinity and compensatory erythremia

During a survey for hemoglobinopathies in over 9000 residents of Hiroshima Prefecture, Japan, a fast moving hemoglobin was identified in eight members of three generations in a Japanese family. The abnormal hemoglobin, named Hb Hiroshima, constitutes about 50% of the total hemoglobin in hemolysates from the carriers who have a mild erythremia but are otherwise apparently clinically unaffected. All preparations of Hb Hiroshima have increased affinity for oxygen, by either tonometric or oxygen electrode determinations. At pH 7.0, the oxygen pressure, P(50) required to half saturate an unfractionated hemolysate from a carrier was one-half that of Hb A, and the P(50) of a purified sample containing no Hb A was one-fourth that of Hb A. The pH dependence of the oxygen equilibrium (Bohr effect) is below normal, as shown by the absolute value of the Bohr effect factor which is about half that of Hb A, in the pH range between 7.0 and 7.4. The Hill constant, n, for Hb Hiroshima between pH 7.0 and 7.4 is 2-2.4, compared to 2.8-3 for Hb A under the same conditions, indicating reduction of, but not complete abolition of heme-heme interaction. Urea dissociation and canine hybridization tests located the biochemical lesion in the beta chain. Fingerprints (Ingram), carboxypeptidase digestion, and amino acid analysis demonstrated that the substitution was at residue 143 in the beta chain, where histidine was replaced by aspartic acid.In contrast to other recently described high oxygen affinity mutants that show intact Bohr effects, all three of the major characteristics of the reversible combination of hemoglobin with oxygen (oxygen equilibrium, heme-heme interaction, and pH dependence) are affected in Hb Hiroshima. A tentative interpretation of these effects, relating structure to function, is offered in terms of recently developed models of normal hemoglobin.

Hb himeji or β140 (H18) ALA→ASP a slightly unstable hemoglobin with increased βN-terminal glycation

A fast-moving abnormal hemoglobin found in a diabetic patient was identified as beta 140 (H18) Ala----Asp. It comprised about 40% of the total hemoglobin. The beta N-terminal glycation in the abnormal hemoglobin was estimated to be 3 times as much as that in Hb A in the same blood sample. The abnormal hemoglobin was slightly unstable. Oxygen affinity of the stripped hemoglobin was decreased, but that of red cells from the carrier was slightly higher than normal because of the reduced effect of 2,3-diphosphoglycerate.

Hemoglobin Mizuho or Beta 68 (E 12) Leucine → Proline, a new Ufistarle Variaiit Associated with Severe Hemolytic Anemia

A hitherto undescribed, unstable hemoglobin was discovered in a four-year-old Japanese girl with relatively severe hemolytic anemia requiring monthly blood transfusion Although no abnormal hemoglobin was detectable by electrophoresis at pll 8.6 and 7.0, heat denaturation and isopropanol tests gave positive results.Chemical analyses of the heat labile henioglohin have demonstrated an amino acid substitution of a prolyl for the leucyl residue at the 68th (E 12) position.Remarkable clinical improvement was observed after splenectomy.

Hemoglobin Agenogi (α2β290lys), a slow-moving hemoglobin of a Japanese family resembling Hb-E☆

Abstract A new slow-moving hemoglobin, designated Hb Agenogi, was discovered in a Japanese family in 1965. This hemoglobin was not associated with any clinical or hematological abnormality. It resembled closely Hb-E in electrophoretic and Chromatographic behaviour. Detailed chemical study, however, has established that this hemoglobin can be expressed by the formula α290Lys-a new variant of Hb-A which has not yet been recorded in the list of the abnormal hemoglobins hitherto known to us.

Characterization of β-Thalassemia Mutations Among the Japanese

Characterization of beta-thalassemia mutations were attempted for 29 Japanese families clinically diagnosed as having beta-thalassemia. Following the identification of a mutation by cloning and sequencing, all families were screened for this particular mutation, using biotinylated allele-specific oligonucleotide probes. Seven different mutations were detected in 17 families: Six families had the frameshift mutation at codons 41/42, resulting from a 4 nucleotide deletion (TTCTTT----TT); four had the deletion at codons 127/128 (CAGGCT----CCT); and three had the TATA box mutation at nucleotide -31 (A----G). Four additional families had mutations at codon 24 (GGT----GGA), codon 26 (GAG----AAG), IVS-II-654 (C----T) and codon 110 (GTG----CCG), respectively. The newly discovered deletion mutation at codons 127/128, and mutations at nucleotide -31, and at codon 110 are peculiar to Japanese, and have not been found in any other ethnic group. The haplotypes of the beta-globin gene cluster were also determined. Some of the haplotypes and beta-thalassemia mutations are identical to those reported in the Chinese population. However, it is noteworthy that nearly half of the beta-thalassemia mutations were unique to Japanese.

Hemoglobin hikari (α2Aβ261AspNH2: A fast-moving hemoglobin found in two unrelated japanese families☆

Abstract A new, fast-moving abnormal hemoglobin, designated Hb Hikari, was discovered in two independent Japanese families without any marital relation. This hemoglobin is not associated with any clinical and hematological manifestations. Electrophoretically it migrates between Hb A and Hb N at pH 8.6. It produces a layer intermediate between Hb F and Hb A on Amberlite IRC 50 chromatography. The abnormal hemoglobin is contained in the hemolysate more abundantly (about 60%) than Hb A. Detailed chemical study of the hemoglobin has established that it can be expressed by the formula (α2Aβ261AspNH2.

Some observations on the physicochemical properties of hemoglobin MHyde Park

Abstract Hemoglobin M Hyde Park (Hb M H ) and its modified product (Hb M H X) in oxygenated form were obtained by Chromatographic procedures. The patients blood containing Hb M H revealed EPR spectra with both high and low spin-type signals. In an O 2 equilibrium study, Hb M H showed similar functional abnormalities to Hb M Saskatoon , a somewhat higher O 2 affinity and a smaller n value than Hb A, and a Bohr effect that was almost normal. But the n value and the O 2 affinity of the O 2 equilibrium curves varied considerably according to the wavelength used for calculation, suggesting the conformational change of the abnormal subunit of Hb M H . The abnormal subunit of methemoglobin M H was able to react with cyanide, and its K ′ value was similar to that of Hb M Boston . Heat-denaturation also disclosed the remarkable instability of Hb M H , which was compatible with the results of the in vivo hematologic study.

Studies on the function of abnormal hemoglobins II. Oxygen equilibrium of abnormal hemoglobins: Shimonoseki, Ube II, Hikari, Gifu, and Agenogi

Abstract Oxygen equilibrium functions of abnormal hemoglobins discovered from Japanese families were studied. Hb Shimonoseki (E3α, Gln → Arg), Hb Ube II (E17α, Asn → Asp), Hb Hikari (E5β, Lys → Asn) and Hb Gifu (EF4β, Asn → Lys) have the same function as that of Hb A. These results further confirm the widely known fact that external residues generally do not have a very important role in the function of hemoglobin. Hb Agenogi (F6β, Glu → Lys), however, has a different function from that of Hb A:it has a slightly but obviously lower oxygen affinity than that of Hb A while the shape of the curve of the Bohr effect and the heme heme interaction are normal. A plausible mechanism for the lower oxygen affinity is proposed from the viewpoint of altered surroundings of oxygen-linked acid groups which are brought about by an interaction between the groups and the newly introduced residue, lysine.

Hemoglobin Hijiyama: A New Fast-Moving Hemoglobin in a Japanese Family

A variant of hemoglobin A, named Hb Hijiyama, found in two generations of a Japanese family living in Hiroshima, Japan, has a higher anodal electrophoretic mobility than hemoglobin A; a gain of two negative charges per molecule is indicated. Fingerprinting and amino acid analysis showed the biochemical anomaly to be in the beta chain at residue 120, where lysine is replaced by glutamic acid. In the heterozygote carriers of the abnormal hemoglobin there is no apparent association with clinical or hematologic abnormalities.

Survey of cord blood Hemoglobin in Japan and Identification of two new γ Chain Variants

Two γ chain variants were discovered during a survey of 2,569 cord bloods of Japanese. One was the first case with mutation of the T-γ; chain, i. e. Hb F Yamaguchi or γ 80 (EF 4) Asp → Asn (75 Thr, 136 Ala). It comprised 33.6 % of Hb F, an unusually high percentage for a γ chain variant. The other concerned with the first report of substitution at E 16, i. e. Hb F Iwata or γ72 (E 16) Gly → Arg (75 Ile, 136 Ala). It comprised 11.0 % which is comparable to the values usually reported in an A-γ chain variant. No clinical consequences have been observed in association with the hemoglobin variants.