Somatostatin is a small cyclic peptide widely expressed throughout the central nervous system (CNS) and peripheral tissues. It has a broad range of biological actions that include the regulation of neurotransmission and secretion and the inhibition of the release of growth hormone (GH), thyroid-stimulating hormone (TSH), gastrointestinal (GI) hormones, pancreatic enzymes, and neuropeptides. Besides, it modulates the rate of gastric emptying, smooth muscle contraction, and intestinal blood flow. It also inhibits the proliferation of both normal and tumor cells. Somatostatin exerts its biological effects by activating specific membrane receptors, termed SSTRs. There are five genes encoding six different SSTRs: SSTR1, SSTR2A, SSTR2B, SSTR3, SSTR4, and SSTR5. SSTR2A and SSTR2B are two splice variants of the same gene. All SSTRs belong to the superfamily of G protein-coupled receptors characterized by seven transmembrane α-helix domains connected by three intra- and three extracellular loops. These receptors are expressed throughout the body, including the CNS, hypothalamus, gastrointestinal tract, and pancreas. All SSTRs associate with the pertussis toxin-sensitive Gi protein and are coupled to adenylate cyclase.
Clinically, SSTRs have been investigated for its therapeutic value in human diseases. Somatostatin analogs have been developed for improving the diagnosis and treatment of cancers. For instance, octreotide long-acting release (LAR) and lanreotide Autogel (ATG) are the two somatostatin analogs currently approved for treatment of acromegaly and neuroendocrine tumors (NETs).
Here, we give an introduction to the following subtypes of human somatostatin receptors and briefly summarize the structure, signaling transduction pathways, somatostatin analog development, current advances, etc.
To aid in the in vitro studies, such as biophysical analyses and function determination of these membrane proteins, Creative Biolabs uses various reconstitution approaches to extract, stabilize, and purify your target of interest. For example, we can prepare your proteins in detergent micelles, and we can optimize the detergent and buffer conditions to maintain protein stability and monodispersity. Moreover, we can reconstitute your proteins in more native-like environments than detergents such as proteoliposomes, and nanodiscs. Other techniques including Lipoparticles and polymers help maximally maintain the native fold and function of the protein. For more information please see the Magic™ membrane protein production platform.
Meanwhile, our Magic™ membrane protein antibody discovery platform helps the development of anti-membrane protein antibodies using different display techniques and the hybridoma technology. We also present DNA immunization service for anti-membrane protein antibody development. For more information, please do not hesitate to contact us.