A NEW beta CHAIN HEMOGLOBIN VARIANT WITH INCREASED OXYGEN AFFINITY: Hb SANTA GIUSTA SARDEGNA [beta 93(F9)Cys -%26gt; Trp; HBB c.282T %26gt; G]

作者：Fais Antonella^*; Sollaino Maria Carla; Barella Susanna; Perseu Lucia; Era Benedetta; Corda Marcella

来源：Hemoglobin, 2012, 36(2): 151-156.

DOI：10.3109/03630269.2011.645982

• Variant hemoglobin (Hb)
• Oxygen affinity
• DNA sequencing

During a screening program for the identification of beta-thalassemia (beta-thal) carriers in Sardinia, Italy, we identified two subjects with increased hemoglobin (Hb) levels and an abnormal Hb variant. The same variant was detected in a family member. DNA sequencing revealed a TGT %26gt; TGG mutation at codon 93 of the beta-globin gene. Structural analysis demonstrated that the cystine residue at position 93 of the beta chain was substituted by tryptophan. %26lt;br%26gt;Since this amino acid substitution had not yet been reported, we designated this variant Hb Santa Giusta Sardegna for the place of birth of the subjects. This amino acid substitution occurs at the tyrosine pocket of the beta chain as well as at the alpha 1 beta 2/alpha 2 beta 1 contact of the quaternary structure of the molecule. The presence of this Hb in the hemolysate causes an increased oxygen affinity, a slightly reduced Bohr effect and a reduced heme-heme interaction (n(50), Hill%26apos;s constant) in comparison with those of Hb A.

• 出版日期2012