Griffithsin mutants
Inventors
O'Keefe, Barry R. • Moulaei, Tinoush • Palmer, Kenneth E. • Rohan, Lisa C. • Fuqua, Joshua L. • Kramzer, Lindsay F.
Assignees
University of Louisville Research Foundation ULRF • University of Pittsburgh • US Department of Health and Human Services
Publication Number
US-11339195-B2
Publication Date
2022-05-24
Expiration Date
2036-02-10
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Abstract
The invention provides modified griffithsin polypeptides comprising the amino acid sequence of SEQ ID NO: 1, as well as corresponding nucleic acids, vectors, cells, fusion proteins, constructs, conjugates, and methods of inhibiting viral infection.
Core Innovation
The invention provides modified griffithsin polypeptides comprising the amino acid sequence of SEQ ID NO: 1 with specified amino acid variants at positions X1, X2, X3, X4, X5, X6, and X7, excluding the wild-type sequence SEQ ID NO: 2. The invention also provides corresponding nucleic acids, vectors, cells, fusion proteins, constructs, conjugates, and methods of inhibiting viral infection by administering these modified griffithsin polypeptides or related compositions.
The invention addresses the problem that, although wild-type griffithsin is a potent antiviral protein active against HIV and other viruses, there remains a need for additional griffithsin compounds with improved properties. Specifically, the modified griffithsin polypeptides are engineered to have improved characteristics such as reduced methionine oxidation, increased shelf-life, improved solubility, and enhanced bioavailability across different pH ranges, overcoming limitations of wild-type griffithsin formulations.
The invention achieves these improvements by introducing mutations at key amino acid positions, including substitutions at position 78 to eliminate methionine oxidation by replacing methionine with amino acids lacking sulfur and charge such as alanine or lysine. Further mutations alter the isoelectric point to optimize solubility and bioavailability in various physiological compartments with differing pH values. The modified griffithsin polypeptides also retain the ability to form dimers, maintaining potency comparable or superior to wild-type griffithsin.
Claims Coverage
The patent includes one independent claim focusing on a specific polypeptide sequence with distinct mutations.
Polypeptide consisting of the amino acid sequence SEQ ID NO: 18
The polypeptide comprises the amino acid sequence SEQ ID NO: 18, which is a modified griffithsin mutant with a substitution at position 78 (M78Q) relative to wild-type griffithsin (SEQ ID NO: 2). This sequence confers improved stability by reducing methionine oxidation and enhancing shelf-life and solubility.
The independent claim covers a specific griffithsin mutant polypeptide with amino acid substitutions that improve oxidative stability and antiviral properties, particularly characterized by the amino acid sequence SEQ ID NO: 18.
Stated Advantages
Reduced methionine oxidation leading to increased protein stability and longer shelf-life of griffithsin formulations.
Improved solubility and bioavailability of the modified griffithsin polypeptides at varying physiological pH ranges.
Retention of dimer formation which is associated with increased antiviral potency compared to monomeric griffithsin.
Documented Applications
Inhibiting viral infections, including HIV-1, HIV-2, influenza (such as H5N1), coronavirus infections (e.g., SARS, MERS), and other viruses listed explicitly in the document.
Therapeutic and prophylactic administration to hosts, including humans, for prevention and treatment of viral infections.
Use as a topical microbicide agent in films or suppositories to prevent viral infections, particularly HIV.
Administration in aerosol or microparticulate powder form for respiratory delivery to prevent influenza infection.
Modification and inclusion in pharmaceutical compositions for oral, topical, rectal, vaginal, parenteral, and transdermal administration to inhibit viruses.
Use in biological samples or inanimate objects for viral sterilization or inactivation.
Delivery by gene therapy techniques using nucleic acid vectors to produce antiviral amounts of griffithsin mutants in vivo or ex vivo.
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