5 results on '"Lanfang Chen"'
Search Results
2. Chemical Probes Reveal Sirt2’s New Function as a Robust 'Eraser' of Lysine Lipoylation
- Author
-
Yingxue Li, Jingyu Li, Hongyan Sun, Wei Xu, Yusheng Xie, Liang Zhang, Shao Q. Yao, Rui Wang, Quan Hao, Jigang Wang, and Lanfang Chen
- Subjects
Proteomics ,Lipoylation ,Lysine ,Plasma protein binding ,010402 general chemistry ,SIRT2 ,01 natural sciences ,Biochemistry ,Catalysis ,Sirtuin 2 ,Colloid and Surface Chemistry ,Humans ,Enzyme kinetics ,biology ,Chemistry ,General Chemistry ,0104 chemical sciences ,HEK293 Cells ,Sirtuin ,biology.protein ,bacteria ,Histone deacetylase ,Peptides ,Protein Binding - Abstract
Lysine lipoylation, a highly conserved lysine post-translational modification, plays a critical role in regulating cell metabolism. The catalytic activity of a number of vital metabolic proteins, such as pyruvate dehydrogenase (PDH), depends on lysine lipoylation. Despite its important roles, the detailed biological regulatory mechanism of lysine lipoylation remains largely unexplored. Herein we designed a powerful affinity-based probe, KPlip, to interrogate the interactions of lipoylated peptide/proteins under native cellular environment. Large-scale chemical proteomics analysis revealed a number of binding proteins of KPlip, including sirtuin 2 (Sirt2), an NAD+-dependent protein deacylase. To explore the potential activity of Sirt2 toward lysine lipoylation, we designed a single-step fluorogenic probe, KTlip, which reports delipoylation activity in a continuous manner. The results showed that Sirt2 led to significant delipoylation of KTlip, displaying up to a 60-fold fluorescence increase in the assay. Further kinetic experiments with different peptide substrates revealed that Sirt2 can catalyze the delipoylation of peptide (DLAT-PDH, K259) with a remarkable catalytic efficiency (kcat/Km) of 3.26 × 103 s-1 M-1. The activity is about 400-fold higher than that of Sirt4, the only mammalian enzyme with known delipoylation activity. Furthermore, overexpression and silencing experiments demonstrated that Sirt2 regulates the lipoylation level and the activity of endogenous PDH, thus unequivocally confirming that PDH is a genuine physiological substrate of Sirt2. Using our chemical probes, we have successfully established the relationship between Sirt2 and lysine lipoylation in living cells for the first time. We envision that such chemical probes will serve as useful tools for delineating the roles of lysine lipoylation in biology and diseases.
- Published
- 2019
3. Fluorescent Probes for Single-Step Detection and Proteomic Profiling of Histone Deacetylases
- Author
-
Quan Hao, Danyang Wang, Shao Q. Yao, Yi Wang, Haipeng Lei, Ganchao Chen, Jingyan Ge, Sijun Pan, Hongyan Sun, Huatang Zhang, Bo Peng, Yusheng Xie, and Lanfang Chen
- Subjects
Proteomics ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Histone Deacetylases ,Catalysis ,Residue (chemistry) ,Colloid and Surface Chemistry ,Humans ,Moiety ,Fluorescent Dyes ,chemistry.chemical_classification ,Molecular Structure ,biology ,010405 organic chemistry ,Proteomic Profiling ,General Chemistry ,Fluorescence ,0104 chemical sciences ,Enzyme ,Histone ,chemistry ,biology.protein ,Amine gas treating - Abstract
Histone deacetylases (HDACs) play important roles in regulating various physiological and pathological processes. Developing fluorescent probes capable of detecting HDAC activity can help further elucidate the roles of HDACs in biology. In this study, we first developed a set of activity-based fluorescent probes by incorporating the Kac residue and the O-NBD group. Upon enzymatic removal of the acetyl group in the Kac residue, the released free amine reacted intramolecularly with the O-NBD moiety, resulting in turn-on fluorescence. These designed probes are capable of detecting HDAC activity in a continuous fashion, thereby eliminating the extra step of fluorescence development. Remarkably, the amount of turn-on fluorescence can be as high as 50-fold, which is superior to the existing one-step HDAC fluorescent probes. Inhibition experiments further proved that the probes can serve as useful tools for screening HDAC inhibitors. Building on these results, we moved on and designed a dual-purpose fluorescent probe by introducing a diazirine photo-cross-linker into the probe. The resulting probe was not only capable of reporting enzymatic activity but also able to directly identify and capture the protein targets from the complex cellular environment. By combining a fluorometric method and in-gel fluorescence scanning technique, we found that epigenetic readers and erasers can be readily identified and differentiated using a single probe. This is not achievable with traditional photoaffinity probes. In light of the prominent properties and the diverse functions of this newly developed probe, we envision that it can provide a robust tool for functional analysis of HDACs and facilitate future drug discovery in epigenetics.
- Published
- 2016
4. Determinants and the Moderating Effect of Perceived Policy Effectiveness on Residents’ Separation Intention for Rural Household Solid Waste
- Author
-
Lanfang Chen, Shuang Zhang, Dingtao Zhao, and Chuanhui Liao
- Subjects
Rural Population ,China ,Municipal solid waste ,Health, Toxicology and Mutagenesis ,media_common.quotation_subject ,Separation (statistics) ,lcsh:Medicine ,050109 social psychology ,Intention ,010501 environmental sciences ,Environment ,Garbage ,Models, Psychological ,Solid Waste ,01 natural sciences ,Article ,Waste Management ,Perception ,Surveys and Questionnaires ,Humans ,0501 psychology and cognitive sciences ,waste separation ,0105 earth and related environmental sciences ,media_common ,Family Characteristics ,Motivation ,Public economics ,05 social sciences ,lcsh:R ,rural household solid waste ,extended theory of planned behavior ,inducement policy ,capacity building policy ,Public Health, Environmental and Occupational Health ,Capacity building ,Policy ,Attitude ,Social Conditions ,Survey data collection ,Female ,Rural area ,Psychology - Abstract
Currently, villages “besieged with garbage” have become a serious problem in rural areas of China. Separation of rural residential solid waste (RRSW) is one of the main strategies for waste reduction. Although previous studies have analyzed the social and psychological motivations of residents’ separation intention for municipal solid waste (MSW), little attention has been paid to the situation in rural areas. This paper investigates key factors influencing rural residents’ separation intention, as well as analyzing the moderating effects of perceived policy effectiveness on the relationship between the determinants and the intention, using survey data of 538 rural residents in the province of Sichuan in China. The results show that all the proposed key factors influence the separation intention significantly. Furthermore, the policies were divided into two types and the moderating effects were tested for each type. The results show that the perceived effectiveness of both the inducement policy and the capacity building policy moderated the relationship between attitude and separation intention positively, while the perceived effectiveness of the inducement policy moderated the relationship between subjective norms and intention negatively. The findings provide insightful information for policymakers to design effective RRSW separation policies.
- Published
- 2018
5. [Clinical observation of sleeping disorder in children with encephalopathy treated with acupuncture at head points and seed-pressure at ear points]
- Author
-
Shugui, Lai, Qiang, Wu, Lanfang, Chen, Qianru, Huang, and Xuejun, Zhang
- Subjects
Male ,Sleep Wake Disorders ,Brain Diseases ,Child, Preschool ,Acupuncture Therapy ,Acupuncture, Ear ,Humans ,Infant ,Female ,Child ,Sleep ,Acupuncture Points - Abstract
To compare the difference of clinical efficacy on sleeping disorder in the children with encephalopathy between the combined therapy of acupuncture at head points and seed-pressure at ear points and the simple acupuncture at head points.Thirty cases of sleeping disorder induced by encephalopathy werei randomized into an observation group and a control group, 15 cases in each one. In the observation group, the combined therapy of acupuncture at head points and seed-pressure at ear points was adopted. The head points in cluded Sishencong (EX-HN 1), Shenting (GV 24) and Benshen (GB 13). The ear points were the positive reactive sites in the cymba and cavum conchae. In the control group, acupuncture was applied simply to the acupoints on the head. The treatment was given once on every Tuesday and Friday a week separately, 30 min each time. Totally, 16 treatments were required. Children's sleeping habit questionnaire (CSHQ) was used to observe the sleep improvements and the efficacy in the patients of the two groups.In the observation group, the results of sleep resistance, sleep anxiety, night sleep wake, parasomnias, sleep dyspnea, daytime somnolence and the total score after treatment were all improved apparently as compared with those before treatment (all P0. 05). In the control group, the results of night sleep wake, parasomnias, daytime somnolence and the total score after treatment were improved apparently than those before treatment (all P0. 05). In the observation group, the results of sleep resistance, sleep dyspnea and the total score after treatment were better than those in the control group (all P0. 05) and the scores of sleep anxiety and daytime somnolence in the control group were better than those in the observation group after treatment (both P0. 05).The combined therapy of acupuncture at head points and seed-pressure at the positive reactive sites in the cymba and cavum conchae achieves the superior efficacy on sleep resistance and sleep dyspnea as compared with the simple acupuncture. The efficacy of simple acupuncture is more satisfactory on sleep anxiety and daytime somnolence.
- Published
- 2015
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.