ISOMERASE, HYDROLASE AND REDUCTASE ENZYMES IN THE EYE

眼睛中的异构酶、水解酶和还原酶

• 批准号: 2162721
• 负责人: NICHOLAS S BODOR
• 金额: $ 21.63万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-01-01 至 1996-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2162721
• 关键词: aldehyde /ketone oxidoreductase; beta adrenergic agent; chemical group; chemical kinetics; chemical structure; cis trans isomerization; cornea; drug delivery systems; drug design /synthesis /production; drug metabolism; enzyme activity; enzyme substrate complex; eye pharmacology; glaucoma; high performance liquid chromatography; hydrolase; hydrolysis; isomerase; ketones; laboratory rabbit; mathematical model; ocular hypotensive; oximes; protein purification; reduction; stereochemistry; uvea

DESCRIPTION (Investigator's Abstract): The main objective of the proposal is to investigate various enzyme systems in eye tissues which play a key role in recently developed site-specific and site-activated drug delivery systems, a unique concept for treating eye diseases such as glaucoma, by metabolically targeting medication into the site of action, without systemic side effects. The presence and specificity of such enzymes offer perspectives for their use in developing specific treatments for other ophthalmic diseases. The specific enzymes studied in this proposal involve i) oxime isomerase, ii) oxime hydrolyse, and iii) ketone reductase enzymes. Experiments will be carried out to characterize and attempts will be made to isolate enzymes capable of hydrolyzing oximes thus making the corresponding carbonyl compounds available to further metabolic processes. Primary attention will be given to eye compartments (iris, ciliary body, aqueous humor, cornea) found to be directly involved in ocular biotransformation of topically administered drugs and comparisons will be made with tissues exhibiting high hydrolytic capacity (liver, blood, gastrointestinal tissues). The oxime hydrolase activity and substrate specificity will be estimated in vitro and in vivo, using various oximes related to beta-adrenergic antagonists some of which have already been shown to undergo sequential biotransformation-activation in the eye. Since oximes are subject to isomerization in biological media either by enzymatically or by acid-catalyzed reaction and the E- and Z-isomers tend to form an equilibrium mixture, the enzymatic basis of the interplay between oxime hydrolysis and isomerization will also be studied. Preliminary recent data demonstrated that there is indeed a fast enzymatic E-Z interconversion of these oximes, which appears to be sensitive to structural features. Experiments also will be carried out to characterize and attempts will be made to isolate and purify and carbonyl reductase enzyme(s) found in the eye which is responsible to the conversion of certain oxo-compounds to the corresponding alcohols in the presence of NAD(P)H coenzyme. Primary attention will be given to those eye compartments that are directly involved in the ocular biotransformation of topically administered drugs, i.e., to the iris and the ciliary body. Issues on activity, substrate specificity and stereo-specificity (where appropriate) will be approached by in vitro and in vivo experiments involving various carbonyl compounds related to the beta-adrenergic agents. Derivatives (oximes, methoximes), which may be hydrolytically activated prior to the subsequent reduction step, will also be included. These compounds have direct relevance for treating specific eye diseases such as glaucoma, and their activity is principally confined to one of the possible stereoisomeric forms. Correlation between the enzyme activity/stereoselectivity and the structure (along with derived physicochemical properties such as partition coefficient) of the substrates will be determined. The ultimate objective is to facilitate discovery of novel site-and stereospecific delivery of ophthalmic drugs via the chemical delivery system concept.

描述（研究者的摘要）：提案的主要目的 正在研究眼组织中的各种酶系统，这些酶系统发挥了钥匙 在最近开发的现场特异性和现场激活药物中的作用 系统，一种用于治疗眼部疾病（例如青光眼）的独特概念 代谢将药物靶向动作部位，没有 系统性副作用。 此类酶的存在和特异性提供 它们用于开发其他特定治疗的观点 眼科疾病。 该提案中研究的特定酶 涉及i）氧电异构酶，ii）氧电水解和iii）酮还原酶 酶。 实验将进行表征和尝试 将制定以分离能够水解氧气的酶，从而使 相应的羰基化合物可用于进一步代谢 过程。 将对眼室的主要关注（虹膜， 发现直接参与的睫状体，水性幽默，角膜） 局部施用的药物和比较的眼部生物转化 将由表现出高水解能力的组织制成（肝脏， 血液，胃肠道组织）。 催电水解酶活性和 底物特异性将在体外和体内估计 与β-肾上腺素能拮抗剂相关的各种氧气 已经显示出在 眼睛。 由于氧气在生物学培养基中受到同构化 通过酶或通过酸催化反应以及E-和E-和 z-异构体倾向于形成平衡混合物，这是酶促的基础 还将研究氧电水解和异构化之间的相互作用。 初步数据表明，确实存在快速酶促的 这些氧气的E-Z互转换，似乎对 结构特征。 还将进行实验以表征 并尝试隔离和净化和羰基还原酶 在眼中发现的酶，这是负责转化的 在存在的情况下，某些与相应醇的氧化合物 NAD（P）H辅酶。 那些眼睛将主要关注 直接参与眼部生物转化的隔室 局部施用药物，即虹膜和睫状体。 有关活动，底物特异性和立体特异性的问题（其中 适当的体外和体内实验将接近） 涉及与β-肾上腺素能有关的各种羰基化合物 代理商。 衍生物（Oximes，Methoximes），可能是水解的 在随后的减少步骤之前被激活，还将包括在内。 这些化合物在治疗特定眼部疾病方面具有直接相关性 例如青光眼及其活性主要仅限于其中一个 可能的立体异构形式。 酶之间的相关性 活动/立体选择性和结构（加上 理化特性，例如分区系数） 将确定底物。 最终目标是促进 发现新颖的现场和眼科药物的立体传递 通过化学输送系统概念。