Patents by Inventor Fenfei LENG

Fenfei LENG has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 12371725
    Abstract: A method, which synthesizes closed circular single-stranded and double-stranded DNA molecules using in vitro enzymatic systems, is described. Circular single-stranded DNA molecules and double-stranded DNA molecules (e.g., relaxed, or supercoiled) with various sizes can be synthesized. Unwanted DNA molecules, e.g., unligated oligomers, can be removed by exonucleases, such as T5 exonuclease, T7 exonuclease, lambda exonuclease, E. coli exonuclease I and/or III. A method of converting the single-stranded circular DNA molecules into double-stranded circular DNA molecules is also described. The single-stranded and double-stranded circular DNA molecules can be used in a variety of applications.
    Type: Grant
    Filed: October 25, 2023
    Date of Patent: July 29, 2025
    Assignee: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventor: Fenfei Leng
  • Publication number: 20250090566
    Abstract: The subject invention provides fluorophore-quencher nucleic acid molecules comprising relaxed or supercoiled DNA molecules, and their use in rapid and efficient high-throughput screening (HTS) assays to screen and identify compounds that inhibit DNA gyrases. These compounds can be used as antibiotics for treating bacterial infections, especially, multidrug resistant bacterial infections.
    Type: Application
    Filed: October 21, 2024
    Publication date: March 20, 2025
    Applicant: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventors: FENFEI LENG, EDDY ALFONSO, ZIFANG DENG
  • Patent number: 12234504
    Abstract: The subject invention provides a novel fluorescence-based, T5 exonuclease-amplified DNA cleavage assay for gyrase poisoning inhibitor discovery. According to the assay, multiple gyrase molecules can simultaneously bind to a plasmid DNA molecule to form multiple gyrase-DNA cleavage complexes on the same plasmid. These gyrase-DNA cleavage complexes, greatly stabilized by a gyrase poisoning inhibitor, and can be trapped by a detergent such as sarkosyl. Digestion of gyrase by proteinase K results in the production of small DNA fragments, which can be digested by T5 exonuclease. This fluorescence-based DNA cleavage HTS assay is also suitable for screening large compound libraries to identify inhibitors against DNA topoisomerases, including human DNA topoisomerase II?.
    Type: Grant
    Filed: October 1, 2024
    Date of Patent: February 25, 2025
    Assignee: The Florida International University Board of Trustees
    Inventors: Fenfei Leng, Matthew Dias
  • Patent number: 12121528
    Abstract: The subject invention provides fluorophore-quencher nucleic acid molecules comprising relaxed or supercoiled DNA molecules, and their use in rapid and efficient high-throughput screening (HTS) assays to screen and identify compounds that inhibit DNA gyrases. These compounds can be used as antibiotics for treating bacterial infections, especially, multidrug resistant bacterial infections.
    Type: Grant
    Filed: September 13, 2022
    Date of Patent: October 22, 2024
    Assignee: The Florida International University Board of Trustees
    Inventors: Fenfei Leng, Eddy Alfonso, Zifang Deng
  • Publication number: 20240141400
    Abstract: A method, which synthesizes closed circular single-stranded and double-stranded DNA molecules using in vitro enzymatic systems, is described. Circular single-stranded DNA molecules and double-stranded DNA molecules (e.g., relaxed, or supercoiled) with various sizes can be synthesized. Unwanted DNA molecules, e.g., unligated oligomers, can be removed by exonucleases, such as T5 exonuclease, T7 exonuclease, lambda exonuclease, E. coli exonuclease I and/or III. A method of converting the single-stranded circular DNA molecules into double-stranded circular DNA molecules is also described. The single-stranded and double-stranded circular DNA molecules can be used in a variety of applications.
    Type: Application
    Filed: October 25, 2023
    Publication date: May 2, 2024
    Applicant: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventor: Fenfei LENG
  • Publication number: 20230364057
    Abstract: The subject invention provides fluorophore-quencher nucleic acid molecules comprising relaxed or supercoiled DNA molecules, and their use in rapid and efficient high-throughput screening (HTS) assays to screen and identify compounds that inhibit DNA gyrases. These compounds can be used as antibiotics for treating bacterial infections, especially, multidrug resistant bacterial infections.
    Type: Application
    Filed: April 26, 2023
    Publication date: November 16, 2023
    Inventors: Fenfei LENG, Eddy ALFONSO, Zifang DENG, Adel NEFZI, Kyle ROHDE
  • Patent number: 11732286
    Abstract: The present invention provides assays and methods for studying DNA topology and topoisomerases. The assays and methods utilize a circular plasmid DNA comprising one or more hairpin structures and the ability of T5 exonuclease (T5E) to digest the circular plasmid DNA in a specific configuration. The assays and methods can be used as a high throughput screening for inhibitors of, for example, DNA gyrases and DNA topoisomerases I for anticancer drug and antibiotics discovery.
    Type: Grant
    Filed: February 14, 2022
    Date of Patent: August 22, 2023
    Assignee: The Florida International University Board of Trustees
    Inventors: Fenfei Leng, Zifang Deng
  • Publication number: 20230136466
    Abstract: The subject invention provides fluorophore-quencher nucleic acid molecules comprising relaxed or supercoiled DNA molecules, and their use in rapid and efficient high-throughput screening (HTS) assays to screen and identify compounds that inhibit DNA gyrases. These compounds can be used as antibiotics for treating bacterial infections, especially, multidrug resistant bacterial infections.
    Type: Application
    Filed: September 13, 2022
    Publication date: May 4, 2023
    Applicant: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventors: FENFEI LENG, EDDY ALFONSO, ZIFANG DENG
  • Patent number: 11613780
    Abstract: The disclosure describes the effects of transcription mediated from a promoter on the transcription mediated by divergently coupled supercoiling-sensitive promoter. Transcription initiated from a promoter inhibits transcription mediated by a specific supercoiling-sensitive promoter that is divergently coupled to the promoter. A gyrase inhibitor relieves this inhibition and substantially increases the transcription mediated by the specific supercoiling-sensitive promoter that is divergently coupled to another promoter. Accordingly, the invention pertains to a method for identifying a compound as a gyrase inhibitor or not a gyrase inhibitor based on differential expression of genes under the control of divergently coupled promoters in the presence of the compound. Another embodiment of the invention provides an assay for identifying one or more compounds from a library of compounds as a gyrase inhibitor.
    Type: Grant
    Filed: June 15, 2018
    Date of Patent: March 28, 2023
    Assignee: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventors: Fenfei Leng, Xiaoduo Zhi, Samantha Dages, Kelley Dages
  • Publication number: 20220170070
    Abstract: The present invention provides assays and methods for studying DNA topology and topoisomerases. The assays and methods utilize a circular plasmid DNA comprising one or more hairpin structures and the ability of T5 exonuclease (T5E) to digest the circular plasmid DNA in a specific configuration. The assays and methods can be used as a high throughput screening for inhibitors of, for example, DNA gyrases and DNA topoisomerases I for anticancer drug and antibiotics discovery.
    Type: Application
    Filed: February 14, 2022
    Publication date: June 2, 2022
    Applicant: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventors: Fenfei LENG, Zifang DENG
  • Publication number: 20220119858
    Abstract: The present invention provides assays and methods for studying DNA topology and topoisomerases. The assays and methods utilize a circular plasmid DNA comprising one or more hairpin structures and the ability of T5 exonuclease (T5E) to digest the circular plasmid DNA in a specific configuration. The assays and methods can be used as a high throughput screening for inhibitors of, for example, DNA gyrases and DNA topoisomerases I for anticancer drug and antibiotics discovery.
    Type: Application
    Filed: October 16, 2020
    Publication date: April 21, 2022
    Applicant: The Florida International University Board of Trustees
    Inventors: Fenfei LENG, Zifang Deng
  • Patent number: 11286514
    Abstract: The present invention provides assays and methods for studying DNA topology and topoisomerases. The assays and methods utilize a circular plasmid DNA comprising one or more hairpin structures and the ability of T5 exonuclease (T5E) to digest the circular plasmid DNA in a specific configuration. The assays and methods can be used as a high throughput screening for inhibitors of, for example, DNA gyrases and DNA topoisomerases I for anticancer drug and antibiotics discovery.
    Type: Grant
    Filed: October 16, 2020
    Date of Patent: March 29, 2022
    Assignee: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventors: Fenfei Leng, Zifang Deng
  • Patent number: 11268129
    Abstract: The present invention provides assays and methods for studying DNA topology and topoisomerases. The assays and methods utilize a circular plasmid DNA comprising one or more hairpin structures and the ability of T5 exonuclease (T5E) to digest the circular plasmid DNA in a specific configuration. The assays and methods can be used as a high throughput screening for inhibitors of, for example, DNA gyrases and DNA topoisomerases I for anticancer drug and antibiotics discovery.
    Type: Grant
    Filed: June 10, 2021
    Date of Patent: March 8, 2022
    Assignee: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventors: Fenfei Leng, Zifang Deng
  • Patent number: 10150987
    Abstract: The present invention provides labeled circular plasmid DNA molecules for studying DNA topology and topoisomerases. The molecules of the present invention also provide tools for high throughput drug screening for inhibitors of DNA gyrases and DNA topoisomerases for anticancer drug discovery and antibiotics discovery.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: December 11, 2018
    Assignee: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventor: Fenfei Leng
  • Publication number: 20180305755
    Abstract: The disclosure describes the effects of transcription mediated from a promoter on the transcription mediated by divergently coupled supercoiling-sensitive promoter. Transcription initiated from a promoter inhibits transcription mediated by a specific supercoiling-sensitive promoter that is divergently coupled to the promoter. A gyrase inhibitor relieves this inhibition and substantially increases the transcription mediated by the specific supercoiling-sensitive promoter that is divergently coupled to another promoter. Accordingly, the invention pertains to a method for identifying a compound as a gyrase inhibitor or not a gyrase inhibitor based on differential expression of genes under the control of divergently coupled promoters in the presence of the compound. Another embodiment of the invention provides an assay for identifying one or more compounds from a library of compounds as a gyrase inhibitor.
    Type: Application
    Filed: June 15, 2018
    Publication date: October 25, 2018
    Applicant: The Florida International University Board of Trustees
    Inventors: Fenfei LENG, Xiaoduo ZHI, Samantha DAGES, Kelley DAGES
  • Patent number: 10000807
    Abstract: The disclosure describes the effects of transcription mediated from a promoter on the transcription mediated by divergently coupled supercoiling-sensitive promoter. Transcription initiated from a promoter inhibits transcription mediated by a specific supercoiling-sensitive promoter that is divergently coupled to the promoter. A gyrase inhibitor relieves this inhibition and substantially increases the transcription mediated by the specific supercoiling-sensitive promoter that is divergently coupled to another promoter. Accordingly, the invention pertains to a method for identifying a compound as a gyrase inhibitor or not a gyrase inhibitor based on differential expression of genes under the control of divergently coupled promoters in the presence of the compound. Another embodiment of the invention provides an assay for identifying one or more compounds from a library of compounds as a gyrase inhibitor.
    Type: Grant
    Filed: September 1, 2016
    Date of Patent: June 19, 2018
    Assignee: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventors: Fenfei Leng, Xiaoduo Zhi, Samantha Dages, Kelley Dages
  • Publication number: 20180135112
    Abstract: The present invention provides labeled circular plasmid DNA molecules for studying DNA topology and topoisomerases. The molecules of the present invention also provide tools for high throughput drug screening for inhibitors of DNA gyrases and DNA topoisomerases for anticancer drug discovery and antibiotics discovery.
    Type: Application
    Filed: December 28, 2017
    Publication date: May 17, 2018
    Applicant: The Florida International University Board of Trustees
    Inventor: Fenfei LENG
  • Patent number: 9920014
    Abstract: The present invention provides novel bisbenzimidazole compounds and methods of using the compounds as antibacterial agents.
    Type: Grant
    Filed: September 19, 2014
    Date of Patent: March 20, 2018
    Assignees: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES, CLEMSON UNIVERSITY
    Inventors: Nihar Ranjan, Dev P. Arya, Fenfei Leng
  • Publication number: 20180057877
    Abstract: The disclosure describes the effects of transcription mediated from a promoter on the transcription mediated by divergently coupled supercoiling-sensitive promoter. Transcription initiated from a promoter inhibits transcription mediated by a specific supercoiling-sensitive promoter that is divergently coupled to the promoter. A gyrase inhibitor relieves this inhibition and substantially increases the transcription mediated by the specific supercoiling-sensitive promoter that is divergently coupled to another promoter. Accordingly, the invention pertains to a method for identifying a compound as a gyrase inhibitor or not a gyrase inhibitor based on differential expression of genes under the control of divergently coupled promoters in the presence of the compound. Another embodiment of the invention provides an assay for identifying one or more compounds from a library of compounds as a gyrase inhibitor.
    Type: Application
    Filed: September 1, 2016
    Publication date: March 1, 2018
    Applicant: The Florida International University Board of Trustees
    Inventors: Fenfei LENG, Xia duo ZHI, Samantha DAGES, Kelley DAGES
  • Patent number: 9890416
    Abstract: The present invention provides labeled circular plasmid DNA molecules for studying DNA topology and topoisomerases. The molecules of the present invention also provide tools for high throughput drug screening for inhibitors of DNA gyrases and DNA topoisomerases for anticancer drug discovery and antibiotics discovery.
    Type: Grant
    Filed: October 5, 2016
    Date of Patent: February 13, 2018
    Assignee: THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
    Inventor: Fenfei Leng