Identification of abnormal hemoglobins by isoelectric focusing

Using IEF on slabs of acrylamide gel was adapted for screening of abnormal Hemoglobins which are at the same level by electrophoresis on cellulose acetate strips. This method is fast, inexpensive and allowed the simultaneous analysis of 70 samples of whole blood. The characterization technique of IEF allowed us to distinguish some rare variants like Hb O Arab, HbD and T gamma in B 0-thalassemia.     

Analysis of phenotypic manifestations of abnormal human hemoglobins

Phenotypic manifestations of abnormal human hemoglobins are discussed using the data of hematology, protein chemistry and molecular biology. On the basis of the presented analysis it is proposed to distinguish between phenotypic manifestations characterizing the primary molecular defect, i.e. properties of a mutant protein and their expression on the molecular and cellular levels; manifestations characterizing the equilibrium of the primary defect and compensatory potentialities of the organism; and finally the unbalanced state when the compensatory abilities of the organism are depleted. These different manifestations of the same defective gene reflect the most relevant peculiarities of mutant protein properties per se, expression of the properties in the living organism, the influence on the homeostatic system "mutant protein--organism" of the genetic and environmental factors both at the compensation state and at stress.     

A new strategy for structural identification of abnormal human hemoglobins

A new strategy for structural identification of abnormal human hemoglobins is proposed. It is based on micropreparative modification of electrophoretic separation of globins on Cellogel strips with subsequent quantitative isolation of a pure, desalted globin chain, in a form suitable for its subsequent structural investigation. Among the major advantages of the new strategy age possibility to use small blood samples (0.1-0.2 ml), short analysis time, relative simplicity and low cost.     

Improved screening test for abnormal hemoglobins from dried blood samples

Summary A method is described wherin blood samples taken from adults or newborns and dried on filter paper can be used for hemoglobin analysis within 2 years after sampling. The samples are eluted in 8 M urea in the presence of 5% 2-mercaptoethanol and 2% of the neutral detergent Nonidet P-40. Then the individual , , , and chains are separated by means of electrofocusing in 8 M urea-PAA gels. Up to 96 samples can be applied to a gel using multiple syringes. Several hundred samples can be analyzed daily by one person. This method may be especially useful for preventive programs against sickle cell anemia as well as for human mutation monitoring systems.Abbreviations used in this paper PAA polyacrylamide - PAG polyacrylamide gel - TCA trichloroacetic acid - PKU phenylketonuria     

Use of protein database for the computation of the dipole moments of normal and abnormal hemoglobins.

Previously, we discussed the calculation of the dipole moments of small proteins using the three-dimensional protein data-base. Our results demonstrate that the calculated dipole moments are in acceptable agreement with measured values. We, however, noted the difficulty of the calculation with larger proteins, in particular those consisting of several subunits. Hemoglobin (Hb) is a protein having a molecular weight of 64,000 that consists of four subunits, a typical case where the computation was found to be difficult. To circumvent the difficulties, we calculated the dipole moment of each subunit separately. The dipole moment of the whole protein was calculated by the vectorial summation of subunit moments. With this method, the calculated net dipole moment is in good agreement with the experimental value. Our calculation shows that the dipole moment vectors of subunits are, by and large, antiparallel in tetramers causing partial cancellation of the net dipole moment. In addition to normal HbA, the dipole moment of abnormal HbS was calculated using an approximate computational technique. Because of the loss of two negative changes as a result of the replacement of glutamic acid with valine in beta-chains, the dipole moment of HbS was found, experimentally and theoretically, to be significantly smaller than that of HbA.     

Micropreparative thin-layer peptide maps in the molecular diagnosis of abnormal human hemoglobins

General factors determining the possibility of application of peptide maps in thin layer of microcrystalline cellulose as a micropreparative method in molecular diagnostics of abnormal hemoglobins were studied. The effects of absorbtional capacity of cellulose and amino acid impurities in it, choice of eluent and elution technique, peptide structure and extent of its modification in staining as well as completeness and specificity of globin chain enzymatic digestion on peptides extraction from thin layer were analysed. The results of structural identification of Hb D Punjab beta 121 Glu----Gln at a Cypriot; Hb O Arab; beta 121 Glu----Lys at a Bulgarian woman, living in Kalinin region (the second case in the USSR); Hb M Saskatoon beta 63 His----Tyr at a woman from Georgia (the second case in the USSR); Hb Buenos Aires beta 85 Phe----Ser at a Russian girl (the first case in the USSR and the third case in the world); Hb Dagestan alpha 60 Lys----Glu at two members of a Lesgin family from Dagestan; Hb Agenogi beta 90 Glu----Lys at a Hungarian woman; Hb Setif alpha 94 Asp----Tyr at three patients from Cyprus and Hb Detroit beta 95 Lys----Asn at an Azerbaijanian woman (the first case in the USSR and the second case in the world) are presented.     

Type II achondrogenesis-hypochondrogenesis: identification of abnormal type II collagen.

We have extended the study of a mild case of type II achondrogenesis-hypochondrogenesis to include biochemical analyses of cartilage, bone, and the collagens produced by dermal fibroblasts. Type I collagen extracted from bone and types I and III collagen produced by dermal fibroblasts were normal, as was the hexosamine ratio of cartilage proteoglycans. Hyaline cartilage, however, contained approximately equal amounts of types I and II collagen and decreased amounts of type XI collagen. Unlike the normal SDS-PAGE mobility. Two-dimensional SDS-PAGE revealed extensive overmodification of all type II cyanogen bromide peptides in a pattern consistent with heterozygosity for an abnormal pro alpha 1(II) chain which impaired the assembly and/or folding of type II collagen. This interpretation implies that dominant mutations of the COL2A1 gene may cause type II achondrogenesis-hypochondrogenesis. More generally, emerging data implicating defects of type II collagen in the type II achondrogenesis-hypochondrogenesis-spondyloepiphyseal dysplasia congenita spectrum and in the Kniest-Stickler syndrome spectrum suggest that diverse mutations of this gene may be associated with widely differing phenotypic outcome.     

Identification of Hb D-Punjab gene: application of DNA amplification in the study of abnormal hemoglobins.

Hemoglobin D-Punjab (or D-Los Angeles) is a common variant worldwide. It is also the most frequent abnormal hemoglobin in Xinjiang Uygur Autonomous Region of China. A large survey of hemoglobinopathy, including 142,171 people and 21 national/ethnic groups, was carried out in Xinjiang and indicated Hb D-Punjab accounted for 55.6% of the total hemoglobin variants there. Here we describe a simple way--EcoRI mapping of the amplified beta-globin DNA sampling from dried blood spots on filter paper blotters--of identifying the Hb D-Punjab gene. The primers were designed and synthesized to emzymatically amplify a 144-bp fragment of beta-globin gene which included codons beta 121 (GAA) and 122 (TTC) representing an EcoRI recognition site. The Hb D-Punjab gene could be easily detected by EcoRI digestion of the amplified DNA sequence on agarose gel because of a single base change at codon 121. The analysis of amplified DNA sampling from dried blood provides a very useful method for population study of Hb D-Punjab and will be of significance for demonstration of the occurrence of the Hb D-Punjab gene and for understanding of the relations among various nationalities.