ON STABILITY OF TETRAMER-DIMER INTERFACE OF HUMAN HEMOGLOBINS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。一项持续而富有成效的合作仍在进行中，曼宁教授？他在东北大学和我们的实验室。这项合作努力的实验目标是通过质谱法对人类血红蛋白多肽链中自然发生的或基因工程突变进行完整的表征。最近，我们的实验室与j·埃里克·罗素教授开始了一个项目。在美国实验室研究转基因小鼠产生的胚胎血红蛋白。我们的研究旨在更好地了解血红蛋白四聚体内影响外周组织氧运输效率的远程通信。我们目前正在研究人类血红蛋白四聚体-二聚体界面附近某些氨基酸残基的关系。质谱法被用于表征血红蛋白中构成多肽链的三步方法，包括：(1)通过电喷雾电离质谱法分析多肽链的完整质量；(2)用特定蛋白酶对多肽链进行酶切，利用MALDI-TOF/MS获得多肽图谱；(3)在电喷雾电离离子阱质谱仪上进行质谱碎片化测序。以下手稿已提交出版：MANNING， L. R.；罗素，j.e.；帕多万，j.c.；椅子，b.t.；j·m·曼宁？人胚胎血红蛋白亚基Portland-22)削弱所有亚基相互作用相对于四聚体有？成人血红蛋白A亚基（?2?2）。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. An ongoing and productive collaboration is still in progress between Prof. Manning?s laboratory at Northeastern University and ours. The experimental goal of this collaborative endeavor is at the complete characterization by mass spectrometry of either naturally occurring or genetically engineered mutations in the polypeptide chains of human hemoglobins. Recently, our laboratories began a project with Prof. J. Eric Russell?s laboratory to study embryonic hemoglobins produced in transgenic mice. Our studies aim at a better understanding of the long-range communications within hemoglobin tetramers which affect the efficiency of the oxygen transport to peripheral tissues. We are currently investigating the relationship of certain amino acid residues near the tetramer-dimer interface of human hemoglobin. Mass spectrometry is being used to characterize the constituting polypeptide chains in hemoglobin using a three-step approach that consists in (1) analyzing the intact mass of the polypeptide chains by electrospray ionization mass spectrometry; (2) digesting the polypeptide chains with a specific proteinase and obtaining peptide maps by MALDI-TOF/MS; and (3) sequencing the peptides containing the mutations by mass spectrometric fragmentation on an electrospray ionization ion trap mass spectrometer. The following manuscript has been submitted for publication: MANNING, L. R.; RUSSELL, J. E.; PADOVAN, J. C.; CHAIT, B. T.; MANNING, J. M. ?-subunits in human embryonic hemoglobin Portland-2 (?2?2) weaken all subunit interactions relative to tetramers having ? subunits in adult hemoglobin A (?2?2).