Experimental evidence has been presented to suggest that the human augmenter of liver regeneration （hALR） serves as a hepatotruphic growth factor during liver regeneration and as a generalized growth factor during p...Experimental evidence has been presented to suggest that the human augmenter of liver regeneration （hALR） serves as a hepatotruphic growth factor during liver regeneration and as a generalized growth factor during pancreas transplant/regeneration. A prokaryotic expression plasmid, pRSET/6his-c-myc-hALR was constructed, by cloning synthesized hALR cDNA into pRSET/6his-c-myc that was improved on the basis of pRSET B by the group. As a result, the protein was highly expressed in E. coli BL21. The recombinant hALR was over 60% of the total protein in E. coli. Its validity was confirmed by means of Western Blotting. The protein was purified by Ni-NTA affinity chrumatography and this FAD-dependent sulthydryl oxidase activity was measured.展开更多
Angucyclines are one of the largest families of aromatic polyketides with various chemical structures and bioactivities.Decades of studies have made it easy for us to depict the picture of their early biosynthetic pat...Angucyclines are one of the largest families of aromatic polyketides with various chemical structures and bioactivities.Decades of studies have made it easy for us to depict the picture of their early biosynthetic pathways.Two families of oxygenases,the FAD-dependent oxygenases and the ring opening oxygenases,contribute to the formation of some unique skeletons of atypical angucyclines.The FAD-dependent oxygenases involved in the biosynthetic gene clusters of typical angucyclines catalyze two hydroxylation reactions at C-12 and C-12b of prejadomycin,while their homolog JadH in jadomycin gene cluster catalyze the C-12 hydroxylation and 4a,12b-dehydration reactions of prejadomycin,which leads to the production of dehydrorabelomycin,a common intermediate during the biosynthesis of atypical angucyclines.Ring opening oxygenases of a unique family of oxygenases catalyze the oxidative CeC bond cleavage reaction of dehydrorabelomycin,followed by different rearrangement reactions,resulting in the formation of the various chemical skeletons of atypical angucyclines.These results suggested that the functional differentiation of these oxygenases could apparently enrich the sources of aromatic polyketides with greater structure diversities.展开更多
文摘Experimental evidence has been presented to suggest that the human augmenter of liver regeneration （hALR） serves as a hepatotruphic growth factor during liver regeneration and as a generalized growth factor during pancreas transplant/regeneration. A prokaryotic expression plasmid, pRSET/6his-c-myc-hALR was constructed, by cloning synthesized hALR cDNA into pRSET/6his-c-myc that was improved on the basis of pRSET B by the group. As a result, the protein was highly expressed in E. coli BL21. The recombinant hALR was over 60% of the total protein in E. coli. Its validity was confirmed by means of Western Blotting. The protein was purified by Ni-NTA affinity chrumatography and this FAD-dependent sulthydryl oxidase activity was measured.
基金National Natural Science Foundation of China(Grants:31670800,31470176,and 31130001)Ministry of Science and Technology of China(Grants:2014CB910400).
文摘Angucyclines are one of the largest families of aromatic polyketides with various chemical structures and bioactivities.Decades of studies have made it easy for us to depict the picture of their early biosynthetic pathways.Two families of oxygenases,the FAD-dependent oxygenases and the ring opening oxygenases,contribute to the formation of some unique skeletons of atypical angucyclines.The FAD-dependent oxygenases involved in the biosynthetic gene clusters of typical angucyclines catalyze two hydroxylation reactions at C-12 and C-12b of prejadomycin,while their homolog JadH in jadomycin gene cluster catalyze the C-12 hydroxylation and 4a,12b-dehydration reactions of prejadomycin,which leads to the production of dehydrorabelomycin,a common intermediate during the biosynthesis of atypical angucyclines.Ring opening oxygenases of a unique family of oxygenases catalyze the oxidative CeC bond cleavage reaction of dehydrorabelomycin,followed by different rearrangement reactions,resulting in the formation of the various chemical skeletons of atypical angucyclines.These results suggested that the functional differentiation of these oxygenases could apparently enrich the sources of aromatic polyketides with greater structure diversities.
