Australian Research Council Centre of Excellence for Translational Photosynthesis, Division of Plant Science, Research School of Biology, The Australian National University, Acton, Australian Capital Territory, 2601, Australia.
J Plant Physiol. 2020 Sep;252:153240. doi: 10.1016/j.jplph.2020.153240. Epub 2020 Jul 16.
Rubisco is the primary carboxylase of the photosynthetic process, the most abundant enzyme in the biosphere, and also one of the best-characterized enzymes. Rubisco also functions as an oxygenase, a discovery made 50 years ago by Bill Ogren. Carboxylation of ribulose bisphosphate (RuBP) is the first step of the photosynthetic carbon reduction cycle and leads to the assimilation of CO, whereas the oxygenase activity necessitates the recycling of phosphoglycolate through the photorespiratory carbon oxidation cycle with concomitant loss of CO. Since the discovery of Rubisco's dual function, the biochemical properties of Rubisco have underpinned the mechanistic mathematical models of photosynthetic CO fixation which link Rubisco kinetic properties to gas exchange of leaves. This has allowed assessments of global CO exchange and predictions of how Rubisco has and will shape the environmental responses of crop and global photosynthesis in future climates. Rubisco's biochemical properties, including its slow catalytic turnover and poor affinity for CO, constrain crop growth and therefore improving its activity and regulation and minimising photorespiration are key targets for crop improvement.
核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）是光合作用过程中的主要羧化酶，也是生物界中最丰富的酶之一，同时也是研究最为透彻的酶之一。Rubisco 还具有加氧酶的功能，这一发现是由 Bill Ogren 在 50 年前做出的。核酮糖-1,5-二磷酸（RuBP）的羧化作用是光合作用碳还原循环的第一步，导致 CO 的同化，而加氧酶的活性则需要通过光呼吸碳氧化循环来回收磷酸甘油酸，同时伴随着 CO 的损失。自 Rubisco 双重功能的发现以来，Rubisco 的生化特性为光合作用 CO 固定的机械数学模型提供了基础，该模型将 Rubisco 的动力学特性与叶片的气体交换联系起来。这使得人们能够评估全球 CO 交换，并预测 Rubisco 如何以及将如何在未来气候中塑造作物和全球光合作用的环境响应。Rubisco 的生化特性，包括其缓慢的催化周转率和对 CO 的低亲和力，限制了作物的生长，因此提高其活性和调节能力以及最小化光呼吸是作物改良的关键目标。
