Properties of Carbonic Anhydrase in Chlamydomonas reinhardtii

碳酸酐酶是一种催化二氧化碳和碳酸氢盐离子两种形式无机碳相互转化的酶，在生理条件下占主导地位。在包括莱茵衣藻在内的各种单细胞绿藻中，一种或多种形式的碳酸酐酶是无机碳浓缩系统的关键组成部分，该系统使这些生物能够有效地利用环境中低水平的二氧化碳，否则会限制它们的生长。本项目研究了莱茵衣藻胞外碳酸酐酶在体内和体外的结构性质，并研究了这种结构对酶的催化性能的影响。通过化学交联和直接细胞结合研究，可以更清楚地确定莱茵梭菌胞外酶的定位。此外，稳定，纯化和定位的胞内形式的酶(s)将进行研究。这些研究对于确定莱茵衣藻的成分和描述其有效浓缩无机碳为光合作用提供二氧化碳的机制细节至关重要。对提高作物光合能力具有潜在的应用价值

Carbonic anhydrase is an enzyme which catalyzes the interconversion of the two forms of inorganic carbon, carbon dioxide and bicarbonate ion, which predominate under physiological conditions. In various species of unicellular green algae, including Chlamydomonas reinhardtii, one or more forms of carbonic anhydrase are critical components of an inorganic carbon concentrating system which allows these organisms to efficiently utilize the low levels of ambient carbon dioxide which would otherwise limit their growth. This project investigates the nature of the structure of the extracellular form of carbonic anhydrase in Chlamydomonas reinhardtii in vivo an in vitro and examines the effect of this structure on the catalytic properties of the enzyme. The localization of the extracellular enzyme in C. reinhardtii will be more clearly defined by chemical cross- linking and direct cellular binding studies. In addition, the stabilization, purification and localization of the intracellular form(s) of the enzyme will be investigated. These studies are critical in terms of identifying the components, and describing the details of the mechanism by which Chlamydomonas reinhardtii is able to efficiently concentrate inorganic carbon to provide carbon dioxide for photosynthesis. It is potentially useful for improving photosynthetic capacity of crop plants.***//