The binding between NL-101, a novel nitrogen mustard anti-cancer drug, with amino acids and peptides has been investigated by high performance liquid chromatography electrospray tandem mass spectrometry(HPLC/ESI-MS/MS...The binding between NL-101, a novel nitrogen mustard anti-cancer drug, with amino acids and peptides has been investigated by high performance liquid chromatography electrospray tandem mass spectrometry(HPLC/ESI-MS/MS). This study offers supporting data of the interaction among drug and amino acids and peptides, which could potentially explain the cytotoxic and mutagenic effects of the drug. Collision-induced dissociation(CID) experiment demonstrated that under the same collision energy, the amino group combined with NL-101 adducts are sensitive and often produce more fragment ions; the carboxyl group combined with NL-101 adducts are hard to break and display fewer fragment ions. In addition, when other group(like sulfhydryl group) of amino acids binds to NL-101, CID spectra show different fragmentation pattern. These differences could display structural information about the drug adducts and be utilized as location of the authentic binding sites.展开更多
The Cramer–Rao lower bound on range error is modeled for pseudo-random ranging systems using Geiger-mode avalanche photodiodes. The theoretical results are shown to agree with the Monte Carlo simulation, satisfying b...The Cramer–Rao lower bound on range error is modeled for pseudo-random ranging systems using Geiger-mode avalanche photodiodes. The theoretical results are shown to agree with the Monte Carlo simulation, satisfying boundary evaluations. Experimental tests prove that range errors caused by the fluctuation of the number of photon counts in the laser echo pulse leads to the range drift of the time point spread function. The function relationship between the range error and the photon counting ratio is determined by using numerical fitting.Range errors due to a different echo energy is calibrated so that the corrected range root mean square error is improved to 1 cm.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21327010, 21372199)
文摘The binding between NL-101, a novel nitrogen mustard anti-cancer drug, with amino acids and peptides has been investigated by high performance liquid chromatography electrospray tandem mass spectrometry(HPLC/ESI-MS/MS). This study offers supporting data of the interaction among drug and amino acids and peptides, which could potentially explain the cytotoxic and mutagenic effects of the drug. Collision-induced dissociation(CID) experiment demonstrated that under the same collision energy, the amino group combined with NL-101 adducts are sensitive and often produce more fragment ions; the carboxyl group combined with NL-101 adducts are hard to break and display fewer fragment ions. In addition, when other group(like sulfhydryl group) of amino acids binds to NL-101, CID spectra show different fragmentation pattern. These differences could display structural information about the drug adducts and be utilized as location of the authentic binding sites.
基金supported by the National Natural Science Foundation of China(Nos.61101196 and 61271332)the Natural Science Research Foundation of Jiangsu Province(No.168JB510015)
文摘The Cramer–Rao lower bound on range error is modeled for pseudo-random ranging systems using Geiger-mode avalanche photodiodes. The theoretical results are shown to agree with the Monte Carlo simulation, satisfying boundary evaluations. Experimental tests prove that range errors caused by the fluctuation of the number of photon counts in the laser echo pulse leads to the range drift of the time point spread function. The function relationship between the range error and the photon counting ratio is determined by using numerical fitting.Range errors due to a different echo energy is calibrated so that the corrected range root mean square error is improved to 1 cm.
