美国加州大学伯克利分校David F. Savage团队近期取得重要工作进展，他们研究绘制了Rubisco的生化特性全景图谱。相关研究成果2025年1月22日在线发表于《自然》杂志上。

据介绍，Rubisco是生物圈中主要的二氧化碳固定酶，但其动力学缓慢。演化和化学机制在限制其生化功能方面所起的作用仍存在争议。尽管近期研究结果表明，Rubisco的功能潜力范围比之前认知的更为广泛，但旨在调整其生化参数的工程改造工作大多以失败告终。

研究人员开发了一种大规模平行检测方法，利用一种经过基因工程改造、使酶活性与生长相耦合的大肠杆菌，系统地绘制Rubisco的序列功能图谱。针对超过99%的单氨基酸突变体与CO₂浓度进行综合检测，从而能够推断出数千种氨基酸替换所对应的酶促反应速率和CO₂表观亲和力参数。这种方法识别出了许多可耐受突变的高度保守位点，以及能提高CO₂亲和力的罕见突变。

总之，这一研究表明实现显著的生化变化并非难事，而且不同生物来源的Rubisco之间的功能差距是可以跨越的，这为进一步的酶工程改造工作奠定了基础。

附：英文原文

Title: A map of the rubisco biochemical landscape

Author: Prywes, Noam, Phillips, Naiya R., Oltrogge, Luke M., Lindner, Sebastian, Taylor-Kearney, Leah J., Tsai, Yi-Chin Candace, de Pins, Benoit, Cowan, Aidan E., Chang, Hana A., Wang, Rene Z., Hall, Laina N., Bellieny-Rabelo, Daniel, Nisonoff, Hunter M., Weissman, Rachel F., Flamholz, Avi I., Ding, David, Bhatt, Abhishek Y., Mueller-Cajar, Oliver, Shih, Patrick M., Milo, Ron, Savage, David F.

Issue&Volume: 2025-01-22

Abstract: Rubisco is the primary CO2-fixing enzyme of the biosphere1, yet it has slow kinetics2. The roles of evolution and chemical mechanism in constraining its biochemical function remain debated3,4. Engineering efforts aimed at adjusting the biochemical parameters of rubisco have largely failed5, although recent results indicate that the functional potential of rubisco has a wider scope than previously known6. Here we developed a massively parallel assay, using an engineered Escherichiacoli7 in which enzyme activity is coupled to growth, to systematically map the sequence–function landscape of rubisco. Composite assay of more than 99% of single-amino acid mutants versus CO2 concentration enabled inference of enzyme velocity and apparent CO2 affinity parameters for thousands of substitutions. This approach identified many highly conserved positions that tolerate mutation and rare mutations that improve CO2 affinity. These data indicate that non-trivial biochemical changes are readily accessible and that the functional distance between rubiscos from diverse organisms can be traversed, laying the groundwork for further enzyme engineering efforts.

DOI: 10.1038/s41586-024-08455-0

Source: https://www.nature.com/articles/s41586-024-08455-0