Gel filtration of dilute human embryonic hemoglobins reveals basis for their increased oxygen binding

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• 作者：Lois R. Manning^a ; Anthony M. Popowicz^b ; Julio C. Padovan^c ; Brian T. Chait^c ; James M. Manning^a ; ^{j.manning@neu.edu}
• 关键词：Gel filtration ; Hemoglobin ; Subunit assembly ; Oxygen affinity ; Development
• 刊名：Analytical Biochemistry
• 出版年：2017
• 出版时间：15 February 2017
• 年：2017
• 卷：519
• 期：Complete
• 页码：38-41
• 全文大小：812 K
• 卷排序：519

文摘

This report establishes a correlation between two known properties of the human embryonic hemoglobins-- their weak subunit assemblies as demonstrated here by gel filtration at very dilute protein concentrations and their high oxygen affinities and reduced cooperativities reported previously by others but without a mechanistic basis. We demonstrate here that their high oxygen affinities are a consequence of their weak assemblies. Weak vs strong hemoglobin tetramers represent a regulatory mechanism to modulate oxygen binding capacity by altering the equilibrium between the various steps in the assembly process that can be described as an inverse allosteric effect.