Calcium sensing receptors, ligands, compositions, and methods of use

• US 10,639,299 B2
• Filed: 03/29/2017
• Issued: 05/05/2020
• Est. Priority Date: 03/29/2016
• Status: Active Grant

• Current Assignee: Georgia State University Research Foundation, Inc., The Board of Trustees of Michigan State University (Michigan State University), The University of Georgia Research Foundation, Inc.
• Original Assignee: Georgia State University Research Foundation, Inc.
• Inventors: Yang, Jenny Jie, Hu, Jian, Brown, Edward, Moremen, Kelley
• Primary Examiner(s): Henley, III, Raymond J
• Application Number:
  US16/090,380
• Publication Number:
  US 20190111032A1
• Time in Patent Office: 1,133 Days
• Field of Search: 514292
• CPC Class Codes: A61K 31/437 the heterocyclic ring system containing a five-membered ring having nitrogen as a ring hetero atom, e.g. indolizine, beta-carboline
• CPC Class Codes: A61P 5/18 of the parathyroid hormones
• CPC Class Codes: A61P 5/20 for decreasing, blocking or antagonising the activity of PTH
• CPC Class Codes: C07K 14/705 Receptors; Cell surface antigens; Cell surface determinants tumour specific antigens C07K14/4748
• CPC Class Codes: C07K 16/18 against material from animals or humans
• CPC Class Codes: G01N 2500/02 Screening involving studying the effect of compounds C on the interaction between interacting molecules A and B (e.g. A = enzyme and B = substrate for A, or A = receptor and B = ligand for the receptor)
• CPC Class Codes: G01N 33/50 Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing measuring or testing processes involving enzymes or microorganisms, compositions or test papers therefor; processes for forming such compositions, condition responsive control in microbiological or enzymological processes C12Q
• CPC Class Codes: G01N 33/6872 Intracellular protein regulatory factors and their receptors, e.g. including ion channels

Abstract

Described herein are compounds that can bind CaSR and/or a CaSR extracellular domain and formulations thereof. Also described herein are methods of inhibiting CaSR and/or treating a disease or disorder associated with a mutation in CaSR by administering a compound or formulation thereof described herein. Also described herein are assays that can be used to identify compounds that can bind an extracellular domain of CaSR.

Claims

1. A method of treating a disease in a subject, the method comprising the step of:

administering an amount of L-1,2,3,4-tetrahydronorharman-3-carboxylic acid (TNCA) to the subject in need thereof, wherein the subject has a disease associated with a mutation of the extracellular calcium-binding domain (ECD) of a calcium-sensing receptor protein (CaSR) or a disease associated with abnormal CaSR expression or abnormal CaSR activity in a subject in need thereof.

2. The method of claim 1, wherein the amount of TCNA administered modulates the activity of a CaSR.

3. The method of claim 1, wherein the amount of TCNA administered increases the activity of a CaSR.

4. The method of claim 1, wherein the amount of TCNA administered decreases the activity of a CaSR.

5. The method of claim 1, wherein the disease is selected from the group consisting of:

familial hypocalciuric hypercalcemia (FHH), autosomal dominant hypocalcemia (ADH), neonatal severe hyperparathyroidism (NSHPT), primary hyperparathyroidism (PHPT), severe secondary hyperparathyroidism in a patient receiving dialysis treatment for kidney failure, tertiary hyperparathyroidism, persistent or recurrent hyperparathyroidism, hyperparathyroidism occurring after renal transplantation, lithium-induced hyperparathyroidism, hypoparathyroidism, kidney stones, hypomagnesemia, hypermagnesemia, calciphylaxis osteoporosis dysfunction of the CaSR arising from activating or inactivating autoantibodies, hypocalcemia, hypercalcemia, a hypomagnesemia related disease, and a cancer associated with an altered expression of CaSR.

6. The method of claim 1, wherein the ECD has at least one amino acid mutation selected from the group consisting of:

R25X, T138M, N118K, E127K/G/A, C129Y/F/S/R, L125P/F, P55L, C60F, R185Q, Q245R, R220W/P/Q, E250K, R227L, P221L/S, W208S, R172R/K, E297K/D, T151M/R/K, Q164X, and F351V, wherein the mutations are numbered in relation to SEQ ID NO.;

13, and wherein X represents any amino acid other than the wild-type amino acid.

7. The method of claim 1, wherein the TNCA is admixed with a pharmaceutically acceptable carrier.

8. The method of claim 1, wherein the amount is an amount effective to potentiate Ca²⁺ or Mg²⁺ activation of the CaSR.

9. A method comprising:

contacting an extracellular calcium-binding domain (ECD) of a calcium sensing receptor protein (CaSR) with L-1,2,3,4-tetrahydronorharman-3-carboxylic acid (TNCA) and a candidate compound suspected of modulating the activity of the CaSR; and

measuring CaSR activity or TNCA binding to the ECD.

10. The method of claim 9, wherein the L-1,2,3,4-tetrahydronorharman-3-carboxylic acid (TNCA) and the candidate compound simultaneously contact the ECD, and wherein the method comprises the step of directly or indirectly measuring TNCA binding to the ECD.

11. The method of claim 9, wherein the TNCA is detectably labeled.

12. The method of claim 9, wherein the amino acid sequence of the ECD is that of an ECD of a CaSR having amino acid sequence selected from SEQ ID NOS.:

1-18.

13. The method of claim 9, wherein the ECD has at least one mutation compared to an ECD of a CaSR having amino acid sequence selected from SEQ ID NOS.:

1-18.

14. The method of claim 9 wherein the ECD of the CaSR has a binding pocket configured by the amino acids S147, A168, S170, Y218, W70, A298, I416, and E297 of SEQ ID NO.:

13, or equivalents thereof.

15. The method of claim 9, wherein the ECD contains at least one mutation selected from R25X, T138/M, N118 K, E127K/G/A, C129Y/F/S/R, L125P/F, P55L, C60F, R185Q, Q245R, R220W/P/Q, E250K, R227L, P221L/S, W208S, R172R/K, E297K/D, T151M/R/K, Q164X, F351V, wherein the mutations are numbered according to SEQ ID NO.:

13, and wherein X represents any amino acid other than the wild-type amino acid.

16. The method of claim 9, wherein CaSR activity is measured by measuring Ca²⁺ or Mg²⁺ binding to the ECD.