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Y. Jiang 《Biochimica et Biophysica Acta (BBA)/General Subjects》1994,1201(1):76-84
Proteolysis of the hydroxylase component of soluble methane monooxygenase (MMO) with trypsin yielded a protein which retained 50% activity in a standard MMO assay. In an H2O2-driven assay, in which H2O2 replaced two of the protein components, NADH and O2 used in the standard assay, the proteolysed hydroxylase retained full activity for ethane, propane and propene, but had a 2–3 fold increase with methane as substrate. Several crosslinking reagents have been tested for their ability to stabilise the proteolysed form of the hydroxylase. Using polyoxyethylene bis(imidazolyl carbonyl) (Mr 3350) as the crosslinking agent, increased thermostability of the hydroxylase was observed. Activated methoxypolyethylene glycol (Mr 5000) was used to modify the hydroxylase which was now soluble in organic solvents as well as water and could be activated by H2O2. The glycol-modified hydroxylase functioned well in organic solvents in the catalysis of propene oxidation. 相似文献
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Defects in RNA splicing and the consequence of shortened translational reading frames. 总被引:28,自引:8,他引:20 下载免费PDF全文
L. E. Maquat 《American journal of human genetics》1996,59(2):279-286
999.
Seed and leaf extracts ofMammea americana (mamey apple) have a historical use as a biopesticide with the active components previously characterized. We reexamined the utility of this natural bioinsecticide in light of existing sources of material as a by-product of the fruit processing industry. Our results addDiabrotica virgifera virgifera andTrichoplusia ni to the list of insects which are susceptible to the insecticidal ingredients ofM. americana and confirms earlier reports of activity againstBlatella germanica, Periplaneta americana, andPlutella xylostella. We report LD5Os for crude hexane extracts ofM. americana leaves and seeds againstT. ni. These materials represent renewable sources of bioinsecticides for agriculture, and should regenerate interest in coumarin-type compounds for novel pesticidal action. 相似文献
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Varro E. Tyler 《Economic botany》1996,50(1):3-9
In this autobiographical sketch, the author discusses the development of his interest in the biological sciences, crediting his father, his first employer, his high school science teacher, and his college pharmacognosy professor with initially shaping his career. His early work on ergot alkaloid biosynthesis and subsequently, together with students and colleagues, on the toxic constituents of basidiomycetes is detailed. This is followed by comments on his developing interest in the therapeutic utility of herbs and phytomedicinals. A concern with the beneficial use of such products stemmed largely from observations made during sabbatical leaves and frequent travel in Germany. The importance of such botanicals (not currently recognized as drugs in the United States) in our developing health-care system is emphasized. The author concludes his comments by thanking his wife, his teachers, his students, and his many colleagues and friends for their unstinting assistance and support during his entire career. 相似文献