Homo sapiens (human)
Cytokines are proteins that function as hormones signaling events in the body that need a response. They are involved in inflammation and tissue damage. One of these cytokines is interleukin-1. It can act in two ways of signaling: paracrine signaling to neighboring cells and endocrine or hormonal signaling as it travels through the blood to different parts of the body. In paracrine signaling it can activate the production of tissue factor and initiate the cascade of blood clotting. In endocrine signaling it can reduce blood pressure and cause fever by inducing the release of prostaglandins. There are tow type of interleukin-1, interleukin-1-alpha and interleukin- 1beta. In chemical terms, based on their amino acid sequence they are not very similar. However, both interleukins bind to the same type of receptors on cell surfaces.
The structure here shows interleukin-1beta. It contains no alpha helices and twelve beta strands, six of which come together to form a core shaped like a barrel. Its structure is similar to some proteins that act as inhibitors for the protease trypsin. The 12 strands are arranged in a way which gives the molecule approximately 3-fold symmetry along an axis parallel to the barrel axis.
Protein Data Bank (PDB)
author: Arno Paehler