Understanding carbazole biosynthetic enzymes: potential for a versatile assay of acyl CoAs

脂肪酸辅酶A（酰基辅酶A）广泛存在于生物体中，并在许多生物化学反应中发挥核心作用。细胞中酰基辅酶A的异常积累通常是许多疾病（即人类代谢疾病，包括糖尿病、脂肪酸氧化缺乏症（FAOD）和癌症）的诊断症状。到目前为止，已经做出了相当大的努力来开发潜在的诊断工具来测量酰基辅酶A，但结果远非理想。酰基辅酶A也是脂肪酸衍生化学品微生物发酵的关键前体。目前，这些化学品中有许多是从化石来源的原料制备的，需要进行能源密集型加工，许多人认为这些原料在未来是不可持续的。在这方面，微生物发酵是生产这些商品化学品的有吸引力的替代方案，并且增强的酰基CoA生产与工程化微生物中脂肪酸衍生的化学品的生产增加相关。在使酰基CoA增强的过程中，一个关键的挑战通常是量化工程微生物中酰基CoA的水平，但研究人员尚未找到可靠的方法来做到这一点。在这项研究中，我们将研究一种基于酶的系统，该系统具有在温和条件下将酰基辅酶A转化为有色芳香族化合物的能力。这些芳香族化合物是染料材料中常见的基序。因此，将我们的酶系统掺入生物样品中将提供通用且方便的测定来测量给定样品中的酰基CoA浓度。使用细菌酶来完成化学任务在食品工业中得到了很好的建立。可持续制造的好处有据可查。然而，酶法工艺/工业生物技术工艺在精细化工、制药、农业和生物科学工业中的应用仍然不发达。通过研究参与将酰基辅酶A转化为有色芳香族化合物的两种新型酶的催化能力，我们将能够开发其生物技术潜力，作为一种新的灵敏测定方法，使我们能够直接测量各种生物样品中的酰基辅酶A。

Fatty acid coenzyme As (acyl-CoAs) ubiquitously exist in living organisms and play central roles in many biochemical reactions. Abnormal accumulation of acyl-CoAs in cells are often the diagnostic symptoms for many diseases (i.e. human metabolic diseases including diabetes, fatty acid oxidation deficiency (FAOD), and cancers). Considerable efforts have gone into developing potential diagnostic tools to measure acyl CoAs so far and yet the outcomes are far from ideal. Acyl CoAs are also the key precursors for microbial fermentation of fatty acid-derived chemicals. Currently many of these chemicals are prepared from fossil-derived feedstocks which require energy intensive processing, and are considered by many as non-sustainable for the future. In this respect, microbial fermentation is an attractive alternative to produce these commodity chemicals and enhanced acyl CoA production is associated with increased production of fatty acid derived chemicals in engineered microbes. In making acyl CoA enhanced, a key challenge is often to quantify the levels of acyl CoA among engineered microbes but researchers have yet to find a reliable way of doing this. In this study, we are going to investigate an enzyme-based system that has the ability to convert acyl-CoAs into coloured aromatic compounds under mild conditions. These aromatic compounds are common motifs in dye materials. Consequently, the incorporation of our enzymatic system into biological samples will offer a versatile and convenient assay to measure acyl CoA concentration within the given samples. The use of bacterial enzymes to accomplish chemical tasks is well established in the food industry. The benefits in terms of sustainable manufacturing are well documented. However, the application of enzymatic processes/industrial biotechnology processes are still underdeveloped in the fine chemical, pharmaceutical, agricultural and bioscience industries. By working out the catalytic capabilities of the two novel enzymes involved in transforming acyl CoAs into coloured aromatic compounds, we will gain the ability to develop their biotechnological potential to be used as a new sensitive assay that will enable us to directly measure acyl CoAs in various biological samples.