Mutant OPAA enzymes with increased catalytic efficiency on cyclosarin
Inventors
Harvey, Steven P • Dixon, Melissa M • Guelta, Mark A
Assignees
United States Department of the Army • Government of the United States of America
Publication Number
US-10538749-B1
Publication Date
2020-01-21
Expiration Date
2038-01-19
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
The invention comprises isolated, mutant, non-wild-type organophosphorus acid anhydrolase (OPAA) enzymes having two site mutations, methods of production, and methods of use to effectively degrade cylcosarin (GF) (cyclohexyl methylphosphonofluoridate) with greater catalytic efficiency than the wild-type OPAA.
Core Innovation
The invention relates to isolated, mutant, non-wild-type organophosphorus acid anhydrolase (OPAA) enzymes that have two site mutations at sequence positions 212 and 342 of the wild-type sequence SEQ ID NO: 1. These mutants demonstrate increased catalytic efficiency in degrading cyclosarin (GF), a highly toxic chemical nerve agent. The particular mutant with tyrosine at position 212 replaced by phenylalanine, and valine at position 342 replaced by tyrosine, shows approximately ten times greater catalytic efficiency on GF compared to the wild-type OPAA enzyme.
The background identifies the problem as the toxicity of various organophosphorus compounds, including pesticides and chemical warfare nerve agents like GF, which lacks an efficient and easily produced catalyst for environmental or in vivo degradation. While native OPAA enzymes exhibit catalytic activity against some nerve agents, their activity on GF is limited, rendering them marginally useful for decontamination or countermeasure purposes. Therefore, there is a need for new compounds and methods to effectively detoxify GF.
Claims Coverage
The patent contains one independent composition claim directed to a mutant OPAA enzyme and three independent method-related claims covering methods of degrading GF and a kit containing the mutant enzyme. The main inventive features concern specific amino acid substitutions and their use to catalytically degrade GF.
Mutant enzyme with dual substitutions at positions 212 and 342
An isolated mutant OPAA enzyme comprising a non-wild-type amino acid at sequence positions 212 and 342 of SEQ ID NO: 1, specifically Phenylalanine (F) at position 212 and Tyrosine (Y) at position 342.
Use of dual-mutant OPAA to degrade cyclosarin (GF)
A method for degrading GF by contacting GF with a mutant OPAA enzyme having substitutions F at position 212 and Y at position 342 of SEQ ID NO: 1.
Pharmaceutical administration of mutant OPAA for in vivo GF degradation
Administering a pharmaceutical composition containing the mutant OPAA with the specified mutations to a subject to degrade GF, with dosages between about 0.05 to about 1000 µg/mL and administration via injection routes such as intravenous, subcutaneous, or intraperitoneal.
Kit comprising dual-mutant OPAA and pharmaceutically acceptable carrier
A kit containing the isolated mutant OPAA enzyme with mutations at positions 212 and 342 as above, together with a pharmaceutically acceptable carrier, optionally including adjuvants or excipients.
The independent claims collectively cover the composition of the mutant OPAA enzyme with specific amino acid substitutions at positions 212 and 342, methods of using this enzyme to degrade GF including in subjects, and kits comprising the mutant enzyme and carriers, all centered on the enhanced catalytic degradation of GF.
Stated Advantages
Mutant OPAA enzyme exhibits approximately ten times greater catalytic efficiency on the nerve agent GF compared to the wild-type enzyme.
The mutant enzyme demonstrates excellent catalytic activity on GF while maintaining functionality comparable to wild-type OPAA.
The mutations narrow the size of the substrate-binding small pocket, promoting a substrate orientation favorable for efficient catalysis of GF degradation.
Documented Applications
In vivo treatment of GF poisoning by administering the mutant OPAA enzyme.
Catalytic decontamination of surfaces or environments contaminated with GF using the mutant OPAA enzyme.
Pharmaceutical compositions and regimens incorporating the mutant OPAA for degrading GF in subjects.
Use of the mutant OPAA in kits formulated with pharmaceutically acceptable carriers for degradation of GF.
Interested in licensing this patent?