title: Paramagnetic species in beta-thalassemic sera: an ESR study.
abstract: Homozygous beta thalassemic sera show an electron spin resonance (ESR) signal at g approximately  equal to 6 which is not present in normal and heterozygous sera. The signal arises from high spin heme groups exhibiting a departure from tetragonal symmetry toward rhombic. Binding by a serum protein is very likely responsible for such a distortion. In contrast with other authors' findings, we report that heme-human albumin complex shows a similar rhombic distortion. The observed ESR signal at g approximately  equal to 6 is then attributed to this complex.
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D006418:Heme / Q000032:analysis*; D006579:Heterozygote; D006720:Homozygote; D011487:Protein Conformation; D013789:Thalassemia / Q000097:blood*
chemical_list: D006418:Heme