Biomedical subjects

Chang-De Lu

Publications and source records attributed to Chang-De Lu.

21 records · Page 2Linked to original sources

PubMed1996

The Role of DNA Polymerase delta in HeLa Cell DNA Replication Studied by Antisense Technology.

We have investigated the biological role of DNA polymerase delta in HeLa cell DNA replication using antisense technology with the Lipofectin Delivery and the GPT selection method. Both of the oligonucleotides designed to inhibit the expression of DNA polymerase delta and alpha can specifically reduce the DNA replication level in HeLa cells. This is the first report directly proving that DNA polymerase delta plays an important role in mammalian cell DNA replication.

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PubMed1996

Purification and Characterization of DNA Helicase BstH1 from Bacillus stearothermophilus.

We have partially purified a DNA helicase BstH1 from Bacillus stearothermophilus through Polymin P precipitation, ammonia sulfate precipitation and column chromatographic steps with Pheny1-Sepharose, DEAE-cellulose, phosphocellulose, FPLC Mono Q and Superose 12. Bsth1 possesses a DNA-Dependent ATPase activity in the presence of Mg(2+). The ATPase activity of BstH1 is differentially stimulated by the presence of different types of nucleic acids. BstH1 has an optimal ATPase activity at 55 degrees. The DNA helicase activity of BstH1 requires a 3'-terminal single-stranded DNA binding site to initiate the unwinding reaction in the 3' right curved arrow 5'direction. BstH1 can unwind blunt-ended duplex DNA in a concentration-dependent manner.

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PubMed1996

Computer Analysis of the Cleavage Reaction of Hammerhead Ribozyme.

We have analyzed various in vitro cleavage reactions of hammerhead ribozyme by a computer program. Three energy changes: deltaE(s'), deltaE(r'), and deltaE, were calculated. deltaE(s') was the hypothetical energy requirement for the substrate to be activated from the most stable state to the relaxed state. deltaE(r') was the same energy requirement for the ribozyme. deltaE was the calculated free energy decrease by the formation of Rz-S complex from the relaxed ribozyme and the substrate. We found that high deltaE(s') or deltaE(r') reduced the cleavage efficiency of the reaction, and that the deltaE was related to both cleavage efficiency and the optimal temperature of the reaction. deltaE(s'), deltaE(r') can be calculated in advance according to the sequences of the ribozyme and the substrate. Our model, therefore, can be use in the designing of ribozymes.

Journal Article↗