# US 5,346,815 A · Sodium ion binding proteins > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,346,815 A - Document ID: US5346815A - Status: Granted - Kind: A - Application number: 07/938,188 - Filed: 1992-08-28 - Granted: 1994-09-13 - Earliest claimed: 1992-08-28 - Assignees: Mount Sinai School of Medicine of the City University of New York - Inventors: Terry A. Krulwich; D. Mack Ivey - Web page: https://patentgrep.com/patent/US5346815A ## CPC - C07K 14/32: from Bacillus (G) - C12N 15/8241: {Phenotypically and genetically modified plants via recombinant DNA technology} - A61K 38/00: Medicinal preparations containing peptides (peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00) - C07K 2319/23: containing a GST-tag - C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00) - C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00) - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) ## Abstract The present invention relates to the cloning and expression of a sodium ion binding protein. In particular, the invention relates to cloning and expression of a nhaS gene. The nhaS gene product, NhaS, is a protein characterized by binding to and sequestering sodium ion (Na.sup.+). The invention further relates to functional fragments of a sodium ion binding protein, which fragments are characterized by their ability to bind to sodium ion. In a specific embodiment, the fragment is a fragment of NhaS. The gene encoding the sodium binding protein can be introduced into cells to produce desalination bioreactors. The gene encoding the sodium binding protein can also be introduced into plants as a transgene to produce plants that are resistant to sodium. The sodium binding protein itself may be used for treatments involving Na.sup.+ /K.sup.+ ATPase disorders, e.g., in heart disease; the protein also may be introduced parenterally, preferably orally, to bind to and sequester dietary sodium. ## Claims ### Claim 1 A purified and isolated DNA sequence selected from the group consisting of: (a) a DNA sequence encoding the NhaS amino acid sequence of FIG. 1 (SEQ. ID. NO.: 2); (b) a DNA sequence that hybridizes under stringent conditions to the complement of the nhaS DNA sequence of FIG. 1 (Seq. ID No.: 1), wherein the protein encoded by the coding strand of the DNA retains the sodium ion binding function of the NhaS protein; and (c) a DNA sequence that hybridizes under stringent conditions to the coding sequence of the nhaS DNA sequence of FIG. 1 (Seq. ID No.: 1), wherein the protein encoded by the coding strand of the DNA retains the sodium ion binding function of the NhaS protein. ### Claim 2 (depends on 1) A recombinant DNA vector containing the DNA sequence of claim 1. ### Claim 3 (depends on 1) A recombinant DNA vector containing the DNA sequence of claim 1, in which said DNA sequence is linked uninterrupted by stop codons, to a nucleotide sequence that encodes a peptide. ### Claim 4 (depends on 1) The purified and isolated DNA sequence of claim 1, wherein said DNA sequence encodes the NhaS amino acid sequence of FIG. 1 (SEQ. ID. NO.: 2). ### Claim 5 (depends on 2) The recombinant DNA vector of claim 2 in which the sequence is operatively associated with a regulatory sequence that controls gene expression in a host. ### Claim 6 (depends on 3) The recombinant DNA vector of claim 3 in which the nhaS sequence is operatively associated with a regulatory sequence that controls gene expression in a host. ### Claim 7 (depends on 5, 6) An engineered host cell that contains the recombinant DNA vector of claim 5 or 6. ### Claim 8 (depends on 5) An engineered cell line that contains the recombinant DNA expression vector of claim 5 and expresses the nhaS. ### Claim 9 (depends on 6) An engineered cell line that contains the recombinant DNA expression vector of claim 6 and expresses the nhaS. ### Claim 10 (depends on 5) A method for producing recombinant NhaS, comprising: (a) culturing a host cell transformed with the recombinant DNA expression vector of claim 5 and which expresses the NhaS; and (b) recovering the NhaS gene product from the cell culture. ### Claim 11 (depends on 5) A method for producing recombinant nhaS, comprising: (a) culturing a host cell transformed with the recombinant DNA expression vector of claim 5 and which expresses the NhaS; and (b) recovering the NhaS gene product from the cell culture.