Calcitonin
Calcitonin — A 32-amino acid peptide hormone produced by thyroid C-cells that lowers blood calcium levels, studied in bone metabolism and osteoporosis research.
What Is Calcitonin?
Calcitonin is a 32-amino acid peptide hormone (molecular weight: 3418 Da) produced by thyroid C-cells. It contains a disulfide bond between Cys1 and Cys7 and a C-terminal proline amide essential for activity. Calcitonin lowers blood calcium by inhibiting osteoclast-mediated bone resorption, acting as a physiological brake on bone breakdown.
Mechanism of Action
Calcitonin binds the calcitonin receptor (CTR), a class B GPCR on osteoclasts. Receptor activation causes rapid osteoclast retraction from bone surfaces through cytoskeletal rearrangement, directly inhibiting resorption. CTR also heterodimerizes with RAMPs to form the CGRP receptor and amylin receptors.
Clinical and Research Applications
- Osteoporosis: Salmon calcitonin (Miacalcin nasal spray) was an early peptide drug for bone loss
- Pain: Calcitonin has direct analgesic effects independent of its bone actions, studied in fracture pain
- Receptor biology: The calcitonin receptor family (CTR+RAMPs) is a model for understanding GPCR accessory protein modulation
Frequently Asked Questions
What is Calcitonin?
A 32-amino acid peptide hormone produced by thyroid C-cells that lowers blood calcium levels, studied in bone metabolism and osteoporosis research.
Why is Calcitonin important in peptide research?
Calcitonin is a fundamental concept in compound as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.