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High-throughput screening of enzyme mutants by comparison of their activity ratios to an enzyme tag. Anal Biochem 2020; 588:113474. [PMID: 31614116 DOI: 10.1016/j.ab.2019.113474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 10/01/2019] [Accepted: 10/08/2019] [Indexed: 12/16/2022]
Abstract
With Escherichia coli alkaline phosphatase (ECAP) as the tag fused to the N-terminus of Pseudomonas Aeruginosa arylsulfatase (PAAS) and its mutants via a flexible linker, the comparison of the activity ratios of an applicable enzyme and its mutants to a suitable enzyme tag in cell lysates of their fused forms was tested for high-throughput (HTP) screening of mutants. After both the induced expression of a fused form and alkaline lysis of the transformed cells in microplate wells, HTP assay of the activities of ECAP and PAAS/mutant was realized via spectrophotometric-dual-enzyme-simultaneous-assay to derive their activity ratio. The successful induced expression of fused forms required ECAP activities higher than 5.3 U/L in cell lysates. Of three representative fused PAAS/mutants in cell lysates, there were similar proteolytic fragments and the comparison of their activity ratios greatly enhanced the recognition of weakly positive mutants. After saturation mutagenesis at M72 of the fused PAAS, the activity ratios of PAAS/mutants to ECAP in cell lysates of their fused forms were proportional to specific activities of their non-fused counterparts in cell lysates by an immunoturbidimetric assay. Therefore, the proposed strategy was absorbing for both HTP screening of mutants and HTP elucidation of sequence-activity relationship of applicable enzymes.
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Zhang X, He S, Hu X, Wu J, Li X, Liao F, Yang X. Comparison of the Full-Length and 152~528 Truncate of Human Cyclic Nucleotide Phosphodiesterase 4B2 for the Characterization of Inhibitors. Comb Chem High Throughput Screen 2019; 22:49-58. [PMID: 30843483 DOI: 10.2174/1386207322666190306142810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 01/26/2019] [Accepted: 02/15/2019] [Indexed: 11/22/2022]
Abstract
AIM AND OBJECTIVE Human full-length cyclic nucleotide phosphodiesterase isozyme 4B2 (hPDE4B2) as the target for screening and characterizing inhibitors suffers from low activity yield and the coexistence of two conformational states bearing different affinities for (R)-rolipram. Hence, the 152~528 truncate of hPDE4B2 existing only in the low-affinity conformation state for (R)-rolipram was compared against the full-length hPDE4B2 to characterize inhibitors. MATERIALS AND METHODS With 6His-SUMO tag at the N-terminus, both the full-length hPDE 4B2 (SF-hPDE4B2) and the 152~528 truncate (ST-hPDE4B2) were expressed in Escherichia coli cells, purified through Ni-NTA column and compared for the characterization of inhibitors. The inhibition constants (Ki) of some synthesized rolipram analogues against both targets were determined with 96-well microplate through the coupled action of monophosphatase on AMP and spectrophotometric assay of phosphate with malachite green. RESULTS After affinity purification with Ni2+-NTA column, ST-hPDE4B2 showed about 30-fold higher specific activity and 100-fold higher activity yield than SF-hPDE4B2; Ki of (R)-rolipram on ST-hPDE4B2 was consistent with that on the low-affinity state of the untagged full-length hPDE4B2 expressed in insect cells. Of some representative rolipram analogues as inhibitors, a dual-logarithm model quantitatively described their monotonic association, and Ki from 0.010 mM to 8.5 mM against SF-hPDE4B2 was predicted from Ki against ST-hPDE4B2, supporting the discovery of consistent hits by the use of both targets with a pair of properly-set cutoffs. CONCLUSION ST-hPDE4B2 with much higher activity yield may be a favorable alternative target to characterize/screen rolipram analogues as hPDE4B inhibitors in high-throughput mode.
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Affiliation(s)
- Xiang Zhang
- Key Laboratory of Clinical Laboratory Diagnosis of the Education Ministry, College of Laboratory Medicine, Chongqing Medical University, No.1, Yixueyuan Road, Chongqing 400016, China
| | - Shu He
- Key Laboratory of Clinical Laboratory Diagnosis of the Education Ministry, College of Laboratory Medicine, Chongqing Medical University, No.1, Yixueyuan Road, Chongqing 400016, China
| | - Xiaolei Hu
- Key Laboratory of Clinical Laboratory Diagnosis of the Education Ministry, College of Laboratory Medicine, Chongqing Medical University, No.1, Yixueyuan Road, Chongqing 400016, China
| | - Jing Wu
- Key Laboratory of Clinical Laboratory Diagnosis of the Education Ministry, College of Laboratory Medicine, Chongqing Medical University, No.1, Yixueyuan Road, Chongqing 400016, China
| | - Xinpeng Li
- Key Laboratory of Clinical Laboratory Diagnosis of the Education Ministry, College of Laboratory Medicine, Chongqing Medical University, No.1, Yixueyuan Road, Chongqing 400016, China
| | - Fei Liao
- Key Laboratory of Clinical Laboratory Diagnosis of the Education Ministry, College of Laboratory Medicine, Chongqing Medical University, No.1, Yixueyuan Road, Chongqing 400016, China.,School of Pharmacy and Bioengineering, Chongqing University of Technology, Lijiatuo, Chongqing 400054, China
| | - Xiaolan Yang
- Key Laboratory of Clinical Laboratory Diagnosis of the Education Ministry, College of Laboratory Medicine, Chongqing Medical University, No.1, Yixueyuan Road, Chongqing 400016, China
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Yang X, Feng Y, Chong H, Wang D, Hu X, Pu J, Zhan CG, Liao F. High-throughput estimation of specific activities of enzyme/mutants in cell lysates through immunoturbidimetric assay of proteins. Anal Biochem 2017; 534:91-98. [DOI: 10.1016/j.ab.2017.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 05/14/2017] [Indexed: 01/02/2023]
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Data for high-throughput estimation of specific activities of enzyme/mutants in cell lysates through immunoturbidimetric assay of proteins. Data Brief 2017; 14:220-245. [PMID: 28795101 PMCID: PMC5536827 DOI: 10.1016/j.dib.2017.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 06/22/2017] [Accepted: 07/10/2017] [Indexed: 12/01/2022] Open
Abstract
Data in this article are associated with the research article “Highthroughput estimation of specific activities of enzyme/mutants in cell lysates through immunoturbidimetric assay of proteins” (Yang et al., 2017) [1]. This article provided data on how to develop an immunoturbidimetric assay (ITA) of enzyme/mutants as proteins in cell lysates in high-throughput (HTP) mode together with HTP assay of their activities to derive their specific activities in cell lysates for comparison, with Pseudomonas aeruginosa arylsulfatase (PAAS) and Bacillus fastidious uricase (BFU) plus their mutants as models. Data were made publicly available for further analyses.
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Feng Y, Yang X, Wang D, Hu X, Chong H, Liao J, Zhan CG, Liao F. Polyclonal Antibodies in Microplates to Predict the Maximum Adsorption Activities of Enzyme/Mutants from Cell Lysates. Protein J 2017; 36:212-219. [DOI: 10.1007/s10930-017-9716-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Feng T, Yang X, Wang D, Hu X, Liao J, Pu J, Zhao X, Zhan CG, Liao F. A Practical System for High-Throughput Screening of Mutants of Bacillus fastidiosus Uricase. Appl Biochem Biotechnol 2016; 181:667-681. [DOI: 10.1007/s12010-016-2240-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 09/05/2016] [Indexed: 11/28/2022]
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