Structural, Mechanistic and Functional Studies on Oxgenases

蛋白质是一种聚合物，对生命的各个方面都至关重要，它是由单体氨基酸前体聚合产生的。20世纪初，亨利·达金（Henry Dakin）报道了蛋白质能与大气中的氧气发生反应的证据。后来发现青霉素是由三肽（三个相连的氨基酸）与氧反应而制成的。最近，人们发现，调节人类和其他动物如何对氧气供应受限（缺氧）做出反应的蛋白质，在与氧气的直接反应中被修改，以一种降低其活性的方式。这些缺氧诱导因子（hif）与氧气信号的反应，使其降解，从而开启缺氧反应。缺氧反应在人类生物学中具有重要意义。如果我们去高海拔，我们会产生更多的红细胞来弥补氧气供应的减少。红细胞生成是由一种叫做促红细胞生成素（EPO）的激素水平的增加刺激的，而促红细胞生成素又被hfs增加。EPO是一种治疗贫血的重要药物，但它是一种昂贵的蛋白质，并不适合所有贫血患者使用。低氧反应在癌症和健康动物生理发育中也很重要。如果HIF的降解可以被药物阻断，促红细胞生成素水平就会增加，反过来红细胞水平也会增加，也就是说，贫血有了新的治疗方法。博士抑制剂已经被开发出来了，但这些都是相当钝的工具。值得注意的是，同一个加氧酶家族，即利用氧气进行催化的酶，包括催化由三肽前体（实际上是一种微小的蛋白质）形成青霉素的成员，以及HIF介导的人体缺氧反应的关键调节酶——博士酶。BBSRC之前的工作已经能够表征这两种类型的加氧酶，并表明相关酶在生物学的许多其他方面都有作用，包括脂质代谢和快速发展的表观遗传学领域。然而，加氧酶蛋白究竟是如何与氧气相互作用的，目前还不清楚。在我们新提出的BBSRC工作中，我们旨在阐明这一过程的细节。在这样做的过程中，我们的目标是告知溶解气体是如何与蛋白质相互作用的，这是生物学的基本兴趣，包括从进化的角度来看，但在这方面的研究相对较少。我们的工作结果将为如何制造新的抗生素和改进治疗贫血和其他缺氧相关疾病的药物提供信息。这项工作还将使英国在加氧酶研究的基础科学领域保持领先地位，这是一个备受关注的领域（正如2019年诺贝尔奖所认可的那样，英国研究对人体缺氧反应机制的研究做出了贡献）。

Proteins are polymers that are crucial to all aspects of life and which are biologically produced by polymerisation of monomeric amino acid precursors. In the early 20th century evidence was reported (by Henry Dakin) that proteins can react with atmospheric oxygen. Later it was found that penicillins are made from a tripeptide (three linked amino acids) by reaction with oxygen. Much more recently it was found that proteins that regulate how humans and other animals respond to limiting oxygen availability (hypoxia) are modified by direct reactions with oxygen, in a manner that decreases their activity. The reaction of these hypoxia inducible factors (HIFs) with oxygen signals for their degradation, so turning on the hypoxic response. The hypoxic response is of massive importance in human biology. If we go to high altitude we make more red blood cells to compensate for the reduced oxygen availability. Red blood cell production is stimulated by increases in the level of a hormone called erythropoietin (EPO), which in turn is increased by the HIFs. EPO is a really important medicine for the treatment of anaemia, but is an expensive protein to make and is not suitable for use by all anaemia sufferers. The hypoxic response is also important in cancer and the development of healthy animal physiology. If HIF degradation can be blocked by a drug EPO levels will increase and in turn red blood cell levels will increase, i.e. there is a new treatment for anaemia. PHD inhibitors have been developed but these are rather blunt instruments.Remarkably, the same family of oxygenases, i.e. enzymes using oxygen for catalysis, includes members that catalyse formation of penicillins from a tripeptide precursor (in effect a tiny protein) and enzymes that are the key regulators of the HIF mediated human hypoxic response - the PHDs. Previous BBSRC work has enabled the characterisation of these two types of oxygenases and shown related enzymes have roles in many other aspects of biology, including lipid metabolism and in the rapidly emerging field of epigenetics. Exactly how the oxygenase proteins interact with oxygen is not, however, well understood. In our new proposed BBSRC work we aim to elucidate the details of this process. In doing so we aim to inform on how dissolved gases interact with proteins in general, something of fundamental interest in biology, including from an evolutionary perspective, but on which there has been relatively little research. The results of our work will inform on how to make new antibiotics and make improved drugs for the treatment of anaemia and other hypoxic related diseases. The work will also enable the UK to remain at the forefront of basic science in research on oxygenases, a field of intense interest (as recognised by the 2019 Nobel prize for studies on the mechanisms of the human hypoxic response to which UK research contributed).