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Short insertion in a hemoglobin chain: Hb Esch, an unstable α1 variant with duplication of the sequence Ala65-Leu-Thr-Asn68
- Source :
-
Blood Cells, Molecules & Diseases . Sep2003, Vol. 31 Issue 2, p234. 6p. - Publication Year :
- 2003
-
Abstract
- Hemoglobin (Hb) Esch, is an α1 variant, expressed at less than 5%, resulting from the duplication of the 12 nucleotides corresponding to CD65 through 68. The effect of this insertion is the repetition of the sequence Ala-Leu-Thr-Asn, which corresponds to the last turn of helix E. In this variant the presence of a one-turn elongated helix E causes instability and increased ligand affinity. Hb Esch was characterized by DNA sequencing and confirmed by electrospray mass spectrometry. Functional studies were performed by flash photolysis measurements on a fraction isolated by flatbed isoelectric focusing, which was enriched in the abnormal hemoglobin. Similar to other α chain variants due to short insertion (or deletion), Hb Esch probably results from a slipped mispairing mechanism. The stability of such modified proteins depends upon the region which is added or deleted and usually is more stable when involving a flexible loop or complete helix turn(s) near by. [Copyright &y& Elsevier]
- Subjects :
- *HEMOGLOBINS
*NUCLEOTIDE sequence
*DNA
*PROTEINS
Subjects
Details
- Language :
- English
- ISSN :
- 10799796
- Volume :
- 31
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Blood Cells, Molecules & Diseases
- Publication Type :
- Academic Journal
- Accession number :
- 10705689
- Full Text :
- https://doi.org/10.1016/S1079-9796(03)00131-1