RESUMEN
The kinetics of the change from the carboxy to the deoxy conformation of the mutated hemoglobins mentioned in the title and of normal human adult hemoglobin were determined from measurements of light absorption changes occurring up to 50 microseconds after nanosecond-laser photodissociation of the corresponding CO complexes. The spectral evolution of the mutated hemoglobins was found to be similar in its main features to that of normal hemoglobin. The kinetics could be decomposed into two phases with rates 1.1-1.8 x 10(6) s-1 and 0.17-0.34 x 10(6) s-1 (except Hb St. Mandé which displayed only the faster phase). Study of the mutated subunits of HbJ Mexico (alpha subunit) and Hb Hôtel Dieu (beta subunit) showed that they convert exponentially to the stable deoxy state after photodeligation at the same rates as the corresponding subunits of normal Hb: 1.1 x 10(6) s-1 (alpha) and 0.3 x 10(6) s-1 (beta). The results indicate that there is no direct correlation between the kinetics of spectral relaxation in the time range studied and the oxygenation properties for these hemoglobins. However, there is some indication that the kinetics are dependent upon the region of mutation.
Asunto(s)
Hemoglobinas Anormales/metabolismo , Hemoglobina J/metabolismo , Humanos , Cinética , Rayos Láser , Mutación , Oxihemoglobinas/metabolismo , Fotólisis , Factores de TiempoAsunto(s)
Hemoglobinas Anormales , Adulto , Secuencia de Aminoácidos , Aminoácidos/análisis , Cromatografía Líquida de Alta Presión , Femenino , Globinas/aislamiento & purificación , Guyana , Hemoglobinas Anormales/aislamiento & purificación , Humanos , Concentración de Iones de Hidrógeno , Focalización Isoeléctrica , Datos de Secuencia MolecularRESUMEN
Hb J-Cordoba [alpha 2A beta 2(95)(FG2)Lys----Met], is one of the few hemoglobin variants discovered in Argentina. The structure and functional abnormalities are described. Hb J-Cordoba exhibits a slightly increased oxygen affinity, low cooperativity, and normal interaction with heterotropic cofactors.
Asunto(s)
Aminoácidos/análisis , Hemoglobina J/análisis , Hemoglobinas Anormales/análisis , Argentina , Electroforesis de las Proteínas Sanguíneas , Femenino , Humanos , Lactante , Oxígeno/sangre , SolubilidadRESUMEN
Hb Knossos alpha 2 beta 2 27 Ala----Ser was first described in a Greek family as a silent beta(+) thalassemia variant. Reexamination of 5,000 isoelectric focusing patterns of patients with microcytosis allowed the presumptive identification of two additional propositi. The first originated in the French West Indies (Martinique) and the second in Algeria. A branch of the family of the second propositus was also investigated. Identification of Hb Knossos was made easily in the first family since one member was a double heterozygote for Hb S and Hb Knossos. In the second family HPLC elution of the peptide fragments obtained by tryptic digestion of the aminoethylated beta chain allowed the isolation and characterization of an abnormal beta T3 peak with expected beta 27 Ala----Ser substitution. The Hb Knossos heterozygote from Martinique, besides an elevated alpha/beta globin chain ratio, had an elevated Hb A2 concentration in contrast to the Greek and Algerian families in which it was normal. This difference in phenotypes may be explained by the occurrence in the Mediterranean cases of a delta gene abnormality, presumably delta(0) thalassemia, in position cis to the abnormal beta-globin gene.
Asunto(s)
Hemoglobinas Anormales/genética , Talasemia/genética , Adolescente , Adulto , Argelia , Aminoácidos/análisis , Autorradiografía , Niño , Femenino , Hemoglobinas Anormales/análisis , Heterocigoto , Humanos , Focalización Isoeléctrica , Masculino , Martinica , Persona de Mediana Edad , Linaje , Talasemia/sangreRESUMEN
A new abnormal hemoglobin Hb Le Lamentin alpha 20 (B1) His replaced by Gln was discovered during a survey of cord blood from the French West Indies (Martinique). This variant displays an electrophoretic pattern similar to that of Hb A but can be isolated by isoelectric focusing (IEF) and Biorex 70 chromatography. Family studies showed the presence of this hemoglobin variant in the father and in two of his three children. Hematological data from the carriers were normal.
Asunto(s)
Sangre Fetal/análisis , Hemoglobinas Anormales/análisis , Recién Nacido , Adulto , Femenino , Humanos , Focalización Isoeléctrica , Masculino , MartinicaRESUMEN
We report a new case of hemoglobin J. Broussais, present in its heterozygote form in a seven year old child from Martinque. The structural characteristics of this abnormal hemoglobin have been compared by three methods: 1. By analytical and preparative finger-printing on silica gel thin layer plates after tryptic digestion. 2. By a programmed separation of tryptic peptides on various ion exchange resins. 3. And by automatic sequencing of the peptides obtained following CNBr cleavage and separation by gel filtration chromatography. The functional behaviour of this hemoglobin was not modified by the substitution of an Asn for a Lys residue at position 90, although its presence induced slight hematological disorders in the patient. Abnormal hemoglobins which have been identified in Martinique and Guadeloupe are reviewed.