Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Four acid hydrolases are partially sedimentable from cell free extracts of tobacco seedlings; these enzymes have the following pH-optima: acid protease pH 3,5; acid RNase pH 6,2; acid phosphatase pH 5,4 and 5,8 and acid unspecific esterase pH 5,5. 2. After differential centrifugation of cell free extracts the sedimentable hydrolases are recovered in the mitochondrial and microsomal fractions. 3. Treatments of the sedimentable material which destroy cytoplasmic membranes result in the solubilization of the acid hydrolases. 4. Isopycnic centrifugation in sucrose-gradients revealed the presence in cell free extracts of two particulate fractions carrying hydrolases; the relative densities of these particles are 1,11 and 1,09g cm(-3). 5. The lighter fraction consists mainly of spherosomes, as can be demonstrated by fluorescence microscopy of the particles stained with berberine sulfate. The heavier fraction probably consists of so-called prospherosomes. 6. The hydrolases from isolated spherosomes are able to digest isolated mitochondria in vitro. 7. The total activities as well as the quantity of sedimentable fractions are highest in seedlings and decrease markedly during ontogenesis of the plant. 8. The isolation of mature leaves causes the mobilization of the cytoplasm of the mesophyll cells within a few days; the chlorophyll disappears completely within 6 days whereas protein and lipid disappear gradually over a period of 16 days. 9. Immediately after the isolation of the leaves new sedimentable protease and esterase activity is formed; new RNase is synthesized a few days later. Soon after their formation these enzymes appear in the soluble fraction. 10. Treatment of detached leaves with kinetin delays the mobilization of chlorophyll, lipid and protein markedly. In addition the synthesis of acid hydrolases is suppressed almost completely. 11. The spherosomes are viewed as organelles of the plant cells equivalent to the lysosomes of animal cells. The intracellular localization and significance of the hydrolases occuring in the soluble fraction of cell free extracts is discussed. 12. The events taking place in mature detached leaves are interpreted as a catabolic mobilization of the cytoplasm due to the action of the spherosomal enzymes.
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PMID:[Intracellular localization and function of hydrolytic enzymes in tobacco]. 2455 83

Enzyme-activated prodrug therapy (EAPT) is a widely-used and effective treatment method for cancer by converting prodrugs into drugs at the demanded time and space, whose key step is prodrug activation. Traditional prodrug activations are mostly dependent on natural enzymes, which are unstable, expensive and hard to be functionalized. The emerging enzyme mimics, especially the metal-contained enzyme mimics (MEMs), provide a potential chance for improving the traditional EAPT because of their high stability, low cost and easiness of preparation and functionalization. The existing MEMs can be classified into three categories: catalytic core-scaffold MEM (csMEM), nanoparticle MEM (npMEMs) and metal-organic framework (MOF) MEM (mofMEM). These MEMs can mimic diverse functions corresponding to natural enzymes, and some of which are potentially used in prodrug activation, such as DNase, RNase, carbonate esterase, etc. In this review, we briefly summarize the MEMs according to their structure and composition, and highlight the successful and potential applications for prodrug activation mediated by hydrolase-like and oxidoreductase-like MEMs.
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PMID:Designing metal-contained enzyme mimics for prodrug activation. 2841 25


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