Biological application of conjugates derived from oligonucleotides and quinone methides have pre- viously been limited by the slow exchange of their covalent self-adducts and subsequent alkylation of target nucleic ac...Biological application of conjugates derived from oligonucleotides and quinone methides have pre- viously been limited by the slow exchange of their covalent self-adducts and subsequent alkylation of target nucleic acids. To enhance the rates of these processes, a new quinone methide precursor with an electron donating substituent has been prepared. Additionally, this substi- tuent has been placed para to the nascent exo-methylene group of the quinone methide for maximum effect. A conjugate made from this precursor and a 5＇-aminohex- yloligonucleotide accelerates formation of its reversible self-adduct and alkylation of its complementary DNA as predicted from prior model studies.展开更多
Accurate DNA quantitation is a prerequisite in many biomedical and pharmaceutical studies.Here we established a new DNA quantitation method by nuclease P1 digestion and UPLC-MS/MS analysis.DNA fragments can be efficie...Accurate DNA quantitation is a prerequisite in many biomedical and pharmaceutical studies.Here we established a new DNA quantitation method by nuclease P1 digestion and UPLC-MS/MS analysis.DNA fragments can be efficiently hydrolyzed to single deoxyribonucleotides by nuclease P1 in a short time.The decent stabilities of all the four deoxyribonucleotides were confirmed under different conditions.Deoxyadenosine monophosphate(dAMP)was selected as the surrogate for DNA quantitation because dAMP showed the highest sensitivity among the four deoxyribonucleotides in the UPLC-MS/MS analysis.The linear range in DNA quantitation by this method is 1.2-5000 ng/mL.In the validation,the inter-day and intra-day accuracies were within 90%-110%,and the inter-day and intra-day precision were acceptable(RSD<10%).The validated method was successfully applied to quantitate DNA isolated from tumors and organs of a mouse xenograft model.Compared to the quantitation methods using UV absorbance,the reported method provides an enhanced sensitivity,and it allows for the accurate quantitation of isolated DNA with contamination of RNA and ribonucleotide.展开更多
The AidB protein is involved in the adaptive response to DNA alkylation damages in Escherichia coli. Functional proteomic experiments were designed to elucidate AidB biological functions in the presence and in the abs...The AidB protein is involved in the adaptive response to DNA alkylation damages in Escherichia coli. Functional proteomic experiments were designed to elucidate AidB biological functions in the presence and in the absence of methyl methanesulfonate as methylating agent. Several proteins were identified in both conditions and according to their reported biological activities, the inter-actors were grouped into three different functional categories： stress response, energetic metabolic pathways and nucleic acid metabolism. Particularly, the interaction between AidB and UvrA, a member of the UvrABCD nucleotide excision system, suggested a new interesting putative role for AidB.展开更多
文摘Biological application of conjugates derived from oligonucleotides and quinone methides have pre- viously been limited by the slow exchange of their covalent self-adducts and subsequent alkylation of target nucleic acids. To enhance the rates of these processes, a new quinone methide precursor with an electron donating substituent has been prepared. Additionally, this substi- tuent has been placed para to the nascent exo-methylene group of the quinone methide for maximum effect. A conjugate made from this precursor and a 5＇-aminohex- yloligonucleotide accelerates formation of its reversible self-adduct and alkylation of its complementary DNA as predicted from prior model studies.
文摘Accurate DNA quantitation is a prerequisite in many biomedical and pharmaceutical studies.Here we established a new DNA quantitation method by nuclease P1 digestion and UPLC-MS/MS analysis.DNA fragments can be efficiently hydrolyzed to single deoxyribonucleotides by nuclease P1 in a short time.The decent stabilities of all the four deoxyribonucleotides were confirmed under different conditions.Deoxyadenosine monophosphate(dAMP)was selected as the surrogate for DNA quantitation because dAMP showed the highest sensitivity among the four deoxyribonucleotides in the UPLC-MS/MS analysis.The linear range in DNA quantitation by this method is 1.2-5000 ng/mL.In the validation,the inter-day and intra-day accuracies were within 90%-110%,and the inter-day and intra-day precision were acceptable(RSD<10%).The validated method was successfully applied to quantitate DNA isolated from tumors and organs of a mouse xenograft model.Compared to the quantitation methods using UV absorbance,the reported method provides an enhanced sensitivity,and it allows for the accurate quantitation of isolated DNA with contamination of RNA and ribonucleotide.
文摘The AidB protein is involved in the adaptive response to DNA alkylation damages in Escherichia coli. Functional proteomic experiments were designed to elucidate AidB biological functions in the presence and in the absence of methyl methanesulfonate as methylating agent. Several proteins were identified in both conditions and according to their reported biological activities, the inter-actors were grouped into three different functional categories： stress response, energetic metabolic pathways and nucleic acid metabolism. Particularly, the interaction between AidB and UvrA, a member of the UvrABCD nucleotide excision system, suggested a new interesting putative role for AidB.
