Invertebrate Carbonic Anhydrase: A Central Respiratory and Metabolic Enzyme

碳酸酐酶（CA），催化 CO2可逆水合形成碳酸氢根离子和氢 离子，可以潜在地在许多方面发挥重要作用， 各种生理和生化过程，包括 分子和离子种类CO2：CO2运输和排泄， CO2固定用于运动后再生，HCO 3- 掺入氨基甲酰磷酸盐中用于尿素合成。 CA的假定多重功能仅被粗略地研究过 在哺乳动物/脊椎动物系统中， 无脊椎动物 这项研究的目的是 研究鳃膜相关CA在CO2中的作用 呼吸应激条件下甲壳类动物的排泄 (e.g.,运动和从水呼吸到空气呼吸的过渡）。 线粒体CA也将被研究，就其 向代谢途径提供HCO 3-的潜在作用 负责尿素生成和尿素合成。 一 生物化学、生理学和药理学的结合 技术将被用来研究CA分布和功能， 原始系统 主要目标是确定 CA是否是许多不同生物学的核心， 各种各样的原始生物体中的过程。 这项工作 应该提供新的和有用的信息的起源和 的组织模式， 原始系统中的细胞代谢途径。

The enzyme, carbonic anhydrase (CA), which catalyses the reversable hydration of CO2 to form bicarbonate ions and hydrogen ions, can potentially play an important role in a number of varied physiological and biochemical processes which involve the molecular and ionic species CO2 : CO2 transport and excretion, CO2 fixation for post-exercise gluconeogenesis, and HCO3- incorporation into carbamoyl phosphate for urea synthesis. Putative multiple function of CA have been studied only sketchily in mammalian/vertebrate systems and not at all among the invertebrates. The purpose of this proposed research is to investigate the role of branchial membrane-associated CA in CO2 excretion in crustaceans under conditions of respiratory stress (e.g., exercise and the transition from water-to air-breathing). Mitochondrial CA will also be investigated with respect to its potential role in supplying HCO3- to the metabolic pathways responsible for gluconeogenesis and urea synthesis. A combination of biochemical, physiological and pharmacological techniques will be used to study CA distribution and function in primitive systems. The major objectives will be to determine whether or not CA is central to a number of different biological processes in a wide variety of primitive organisms. This work should provide new and useful information on the origins and evolution of CA function and on the pattern of organization of cellular metabolic pathways in primitive systems.