The prolyl hydroxylase 3 (PHD3) protein is less abundant in normal oxygen conditions (normoxia) but increases under deficient oxygen condition (hypoxia). Since cancerous cells often thrive in hypoxic conditions and predominantly express the Pyruvate kinase isoforms 2 (PKM2), the PHD3/PKM2 interaction might be particularly important in cancer development. In the present study, the PHD3/PKM2 complex was co-expressed and purified by size-exclusion chromatography. The interaction of PHD3 with PKM2 was confirmed in Native gel as well as western blot analysis. The PHD3/PKM2 complex formed discreet crystals under suitable conditions, and diffraction data revealed that crystal belonged to the P1 space group with 3.0 Å resolution. This is the first crystal report of PHD3/PKM2 complex as well as this study demonstrates a direct physical binding through protein-protein interaction. The structural analysis of complex will provide the information regarding the amino acid residues critical for the catalytic mechanism. Based on the structural information thus obtained, pharmacological interference with the PHD3/PKM2 interaction could be used as a novel strategy to reduce the cancer progression.

中文翻译：

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脯氨酰羟化酶3 /丙酮酸激酶同工型2蛋白复合物的纯化和表征。

脯氨酰羟化酶3（​​PHD3）蛋白在正常氧气条件下（常氧）含量较低，但在氧气不足条件下（低氧）含量较高。由于癌细胞通常在缺氧条件下生长旺盛并主要表达丙酮酸激酶同工型2（PKM2），因此PHD3 / PKM2相互作用在癌症发展中可能特别重要。在本研究中，PHD3 / PKM2复合物是通过大小排阻色谱法共表达和纯化的。在天然凝胶和蛋白质印迹分析中证实了PHD3与PKM2的相互作用。PHD3 / PKM2复合物在适当的条件下形成了离散晶体，衍射数据显示该晶体属于3.0分辨率的P1空间群。这是PHD3 / PKM2复合物的第一个晶体报告，并且该研究证明了通过蛋白质-蛋白质相互作用的直接物理结合。配合物的结构分析将提供有关催化机理至关重要的氨基酸残基的信息。基于如此获得的结构信息，对PHD3 / PKM2相互作用的药理学干预可以用作减少癌症进展的新策略。