Main observation and conclusion A series of all-donor type alternating(D1-D2)monodisperse oligomers based on cyclopentadithiophene(CPDT)and 1,4-difluoro-benzene(DFB)with gradually increasing chain lengths containing 3...Main observation and conclusion A series of all-donor type alternating(D1-D2)monodisperse oligomers based on cyclopentadithiophene(CPDT)and 1,4-difluoro-benzene(DFB)with gradually increasing chain lengths containing 3 to 15 monomers were successfully synthesized via one-pot C-H direct arylation reaction.As confirmed by various structural characterizations,all these long-chain oligomers are monodispersed with defined structures.The length-dependent optical and electrochemical properties with the evolution from the shortest oligomer(01)to the longest oligomer(07)and their parent polymer P1 have been studied in details.By simply tuning the mixing ratio of discrete oligomers,the photoluminescence(PL)in a wide range of color emissions extending to near-white can be facilely modulated,ilus-trating the potential of these monodisperse conjugated oligomers for light emission application.The atom-,step-and pot-economic synthetic strategy here developed will open the door toward efficient and controllable synthesis ofπ-conjugated oligomers for accu-rate structure-property relationship study and optic&electronic device applications.展开更多
Analysis of proteins that interact with N protein of SARS-CoV using 15-mer phage-displayed library will help to explore the virus pathogenesis and to develop new drugs and vaccines against SARS. In this study,we clone...Analysis of proteins that interact with N protein of SARS-CoV using 15-mer phage-displayed library will help to explore the virus pathogenesis and to develop new drugs and vaccines against SARS. In this study,we cloned,expressed and purified N protein of SARS-CoV. This 46-kD N protein was verified by SDS-PAGE and Western-blot. Then,the peptides binding-specific to N protein were identified using 15-mer phage-displayed library. Surprisingly,all of the 89 clones from monoclonal ELISA were positive (S/N>2.1) and the result was further confirmed experimentally once again. Six N protein-binding pep-tides,designated separately as SNA1,SNA2,SNA4,SNA5,SNA9 and SNG11,were selected for se-quencing. Sequence analysis suggested that SNA5 shared approximatively 100% sequence identity to SNA4,SNA2,SNA9 and SNA1. In addition,the binding specificity of the 15-mer peptides with the SARS-CoV N protein was further demonstrated by blocking ELISA using the synthetical 15-mer peptide according to the deduced amino acid sequence of SNA5. Also,the deduced amino sequence of SNA5 was compared with proteins in translated database using the tblastx program,and the results showed that the proteins with the highest homology were Ubiquinol-cytochrome c reductase iron-sulfur sub-units (UCRI or UQCR),otherwise known as the Rieske iron-sulfur proteins (RISP). Notablely,in the 2Fe-2S redox centre of UCRI,there were 6 residues GGW(Y)F(Y)CP compatible to the residues (po-sition 2→7,GGWFCP7) of the NH2-terminal of the 15-mer peptide,which indicated higher binding specificity between the N protein of SARS-CoV and the redox centre of UCRI to some extent. Here,the possible molecular mechanisms of SARS-CoV N protein in the pathogenesis of SARS are discussed.展开更多
基金The National Natural Science Foundation of China(No.21374075)is appreciated for financial supports.
文摘Main observation and conclusion A series of all-donor type alternating(D1-D2)monodisperse oligomers based on cyclopentadithiophene(CPDT)and 1,4-difluoro-benzene(DFB)with gradually increasing chain lengths containing 3 to 15 monomers were successfully synthesized via one-pot C-H direct arylation reaction.As confirmed by various structural characterizations,all these long-chain oligomers are monodispersed with defined structures.The length-dependent optical and electrochemical properties with the evolution from the shortest oligomer(01)to the longest oligomer(07)and their parent polymer P1 have been studied in details.By simply tuning the mixing ratio of discrete oligomers,the photoluminescence(PL)in a wide range of color emissions extending to near-white can be facilely modulated,ilus-trating the potential of these monodisperse conjugated oligomers for light emission application.The atom-,step-and pot-economic synthetic strategy here developed will open the door toward efficient and controllable synthesis ofπ-conjugated oligomers for accu-rate structure-property relationship study and optic&electronic device applications.
基金the Science and Technology Project of Chongqing Municipal Educa- tion Commission, China (Grant No. KJ071109)the Key Project of the Ministry of Science and Technology of China (Grant No. 2003CB514120)
文摘Analysis of proteins that interact with N protein of SARS-CoV using 15-mer phage-displayed library will help to explore the virus pathogenesis and to develop new drugs and vaccines against SARS. In this study,we cloned,expressed and purified N protein of SARS-CoV. This 46-kD N protein was verified by SDS-PAGE and Western-blot. Then,the peptides binding-specific to N protein were identified using 15-mer phage-displayed library. Surprisingly,all of the 89 clones from monoclonal ELISA were positive (S/N>2.1) and the result was further confirmed experimentally once again. Six N protein-binding pep-tides,designated separately as SNA1,SNA2,SNA4,SNA5,SNA9 and SNG11,were selected for se-quencing. Sequence analysis suggested that SNA5 shared approximatively 100% sequence identity to SNA4,SNA2,SNA9 and SNA1. In addition,the binding specificity of the 15-mer peptides with the SARS-CoV N protein was further demonstrated by blocking ELISA using the synthetical 15-mer peptide according to the deduced amino acid sequence of SNA5. Also,the deduced amino sequence of SNA5 was compared with proteins in translated database using the tblastx program,and the results showed that the proteins with the highest homology were Ubiquinol-cytochrome c reductase iron-sulfur sub-units (UCRI or UQCR),otherwise known as the Rieske iron-sulfur proteins (RISP). Notablely,in the 2Fe-2S redox centre of UCRI,there were 6 residues GGW(Y)F(Y)CP compatible to the residues (po-sition 2→7,GGWFCP7) of the NH2-terminal of the 15-mer peptide,which indicated higher binding specificity between the N protein of SARS-CoV and the redox centre of UCRI to some extent. Here,the possible molecular mechanisms of SARS-CoV N protein in the pathogenesis of SARS are discussed.
