Pancreatic protein hormone
Insulin
Insulin is an endogenous protein hormone. Molecular research should distinguish three entities: the hormone, its receptor and analogs designed from it. Each corresponds to a different experimental question.
This is a research reference, not a product offered in the Asciende catalog. Published studies do not establish the identity, purity or availability of a commercial preparation.
Ligand, receptor and formulation
Keep entity and method together: transferring a result between formulations requires evidence even when their names overlap.
- Is the experimental entity the hormone, a fragment, an analog or a complete formulation?
- Does the readout measure receptor binding, an intracellular signal or an outcome in another system?
- Are species, expressed receptor, comparator and readout time reported?
Mechanism described in the literature
Structural literature describes an insulin receptor combining extracellular recognition regions with an intracellular tyrosine kinase region. Studies of hormone-receptor complexes investigate how binding relates to changes in receptor organization.
Other names in the literature
- Insulin
The hormone is not its receptor
The 1985 cloning study characterized complementary DNA for the human receptor and described regions with different structural functions. It examined the protein recognizing the signal, not the insulin sequence. This prevents attributing receptor catalytic domains to the hormone.
What observing the complex adds
A 2018 investigation used cryo-electron microscopy to reconstruct insulin complexes with the receptor ectodomain. It distinguished occupancy states and contacts between regions. These models provided a structural explanation of recognition without themselves representing a cell's entire metabolic response.
From ectodomain to complete system
An ectodomain preparation preserves the receptor's external region but not every element of an intact cell. A binding structure and a phosphorylation assay therefore provide complementary evidence. The former describes contacts and organization; the latter examines a functional consequence under specific conditions.
Questions and answers
Does a structural image demonstrate metabolic activity?
Not by itself. It describes a molecular preparation; activity requires additional functional measurements and an identified experimental system.
Is every insulin-related molecule human insulin?
No. Analogs, precursors and receptor components must retain their full names. Similarity or participation in the same pathway does not establish identity.
Sources
- The human insulin receptor cDNA: the structural basis for hormone-activated transmembrane signalling. — Cell, 1985
- The human insulin receptor cDNA: the structural basis for hormone-activated transmembrane signalling.
- Structure of the insulin receptor-insulin complex by single-particle cryo-EM analysis. — Nature, 2018
- Structure of the insulin receptor-insulin complex by single-particle cryo-EM analysis.