1071-bp fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the 3′ and 5′ ends of the incomplete expression sequence tag (EST) of succinate dehydrogenase iron-sulfur protei...1071-bp fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the 3′ and 5′ ends of the incomplete expression sequence tag (EST) of succinate dehydrogenase iron-sulfur protein of Schistosoma japonicum (SjSDISP) were amplified by the anchored PCR with 2 pairs of primers designed according to the EST of SjSDISP and the sequence of multiclone sites of the library vector. Sequence analysis indicated that the fragment was a full-length cDNA with a complete open reading frame (ORF), encoding 278 amino acid residues. The fragment was cloned into prokary- otic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coli. SDS-PAGE and Western-blot analyses showed that the recombinant protein was about 32 kD and could be recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Compared with the FCA controls, mice vaccinated with rSjSDISP (test) or rSjGST (posi- tive control) all revealed high levels of specific antibody and significant reduction in worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs. These results suggest that SjSDISP may be a novel and partially protective vaccine candidate against schistosomiasis. In contrast to the worm burden reduction rate, the higher degree of egg reduction rate in the test group also sug- gested that SjSDISP vaccine may primarily play a role in anti-embryonation or anti-fecundity immunity.展开更多
The human pathogen Clostridium difficile infection（CDI） is one of the most important healthcare- associated infections. Methyltransferase（MeTrca） and corrinoid iron-sulfur protein（CoFeSPca） are two key proteins ...The human pathogen Clostridium difficile infection（CDI） is one of the most important healthcare- associated infections. Methyltransferase（MeTrca） and corrinoid iron-sulfur protein（CoFeSPca） are two key proteins in the acetyl-coenzyme A synthesis pathway of Clostridium difficile, which is essential for the survival of the pathogen and is absent in humans. Hence, the interaction between MeTrca and CoFeSPcd can become innovative targets for the treatment of human CDI. In this study, the interaction between MeTrca and CoFeSPca was verified by fluorescence resonance energy transfer measurements. The influence of the interaction on the tertiary structure of MeTrcd and CoFeSPcd was studied by ANS-labeled fluorescence measurements. Molecular docking was also performed to understand the mechanism of the protein interactions. These results provide a molecular basis for innovative drug design and development to treat human CDI.展开更多
基金the China National Tenth "Five-year Plan" Important Special Program (Grant No. 2002AA2Z3343), the China "863" Important Program (Grant No. 2004AA2Z3530), Hunan Province Eleventh "Five-year Plan" Improtant Special Program (Grant No. 2006SK1001), and Hunan Province Tenth "Five-year Key Xueke Plan" (Grant No. 03-985-3-7)
文摘1071-bp fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the 3′ and 5′ ends of the incomplete expression sequence tag (EST) of succinate dehydrogenase iron-sulfur protein of Schistosoma japonicum (SjSDISP) were amplified by the anchored PCR with 2 pairs of primers designed according to the EST of SjSDISP and the sequence of multiclone sites of the library vector. Sequence analysis indicated that the fragment was a full-length cDNA with a complete open reading frame (ORF), encoding 278 amino acid residues. The fragment was cloned into prokary- otic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coli. SDS-PAGE and Western-blot analyses showed that the recombinant protein was about 32 kD and could be recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Compared with the FCA controls, mice vaccinated with rSjSDISP (test) or rSjGST (posi- tive control) all revealed high levels of specific antibody and significant reduction in worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs. These results suggest that SjSDISP may be a novel and partially protective vaccine candidate against schistosomiasis. In contrast to the worm burden reduction rate, the higher degree of egg reduction rate in the test group also sug- gested that SjSDISP vaccine may primarily play a role in anti-embryonation or anti-fecundity immunity.
基金Supported by the National Natural Science Foundation of China（Nos.31270869, 31670817, 21472027, 91013001） and the Phl） Program of the Ministry of Education of China（No.20100071110011）.
文摘The human pathogen Clostridium difficile infection（CDI） is one of the most important healthcare- associated infections. Methyltransferase（MeTrca） and corrinoid iron-sulfur protein（CoFeSPca） are two key proteins in the acetyl-coenzyme A synthesis pathway of Clostridium difficile, which is essential for the survival of the pathogen and is absent in humans. Hence, the interaction between MeTrca and CoFeSPcd can become innovative targets for the treatment of human CDI. In this study, the interaction between MeTrca and CoFeSPca was verified by fluorescence resonance energy transfer measurements. The influence of the interaction on the tertiary structure of MeTrcd and CoFeSPcd was studied by ANS-labeled fluorescence measurements. Molecular docking was also performed to understand the mechanism of the protein interactions. These results provide a molecular basis for innovative drug design and development to treat human CDI.
