Glycoprotein hormones peptide

Neuropeptides - most Peptide hormones - many Glycoprotein hormones Chemokines Protease receptors... 

Erythropoietin is a glycoprotein hormone that regulates the proliferation, differentiation, and maturation of erythroid cells. The EPO receptor is a member of the class 1 cytokine receptor superfamily. The crystal structure of an EPO-mimetic peptide and the extracellular portion of the... 

AMINO ACIDS, PEPTIDES PROTEINS Recommended nomenclature and symbolism for amino acids and peptides J. Biol Chem. (1985) 260, 14-42 Biochemistry (1975) 14, 449-462 Abbreviations and symbols for the description of the conformation of polypeptide chains /. Biol Chem. (1970) 245, 6489-6497 Nomenclature of iron-sulfur proteins Eur. J. Biochem. (1979) 93, 427-430 Corrections Eur. J. Biochem. (1979) 102, 315 Nomenclature of peptide hormones J. Biol Chem. (1975) 250, 3215-3216 Nomenclature of human immunoglobulins Eur. J. Biochem. (1974) 45, 5-6 Recommended nomenclature of glycoproteins, glyco-peptides, and peptidoglycans /. Biol Chem. (1987) 262, 13-18 Recommended nomenclature of electron-transfer proteins... 

After secretion, the hormones circulate in blood for periods ranging from minutes (insulin) to a few hours (glycoprotein hormones). The protein hormones, being water-soluble, circulate in free form and are not bound to specific proteins. Their concentrations in blood are very low, the resting concentrations being 1CT11 M to 10 10 M. Under stimulated conditions the concentrations of peptide hormones in blood may rise 5- to 100-fold. 

Examples of the use of analytical-scale column systems for the small-scale (i.e., 1 fig to 1 mg) preparative separation of peptides include the extraordinarily potent opoid peptide, dynorphin (I4S) insulin A-, B-, and C-chain peptides (24, 72) j8-chain peptides of the pituitary glycoprotein hormones (8) endorphins (28,60, 126, 137), adrenocorticotropic peptides in plasma, pituitary, and other endocrine glands or secreted from tumor cells iVt vitro (84, I2S, 127, 138, 142. I Si) hypothalamic releasing factors... 

Figure 7. A schematic diagram of the proposed ligand binding domains, shown in light grey, in various GPCRs. The helices are shown as cylinders, the loops, N-termini and C-termini are shown as lines. (A) Biogenic amine receptors, (B) Peptide receptors, (C) Glycoprotein hormone receptors, (D) Thrombin receptor.

Hormones can be glycoproteins, polypeptides, peptides, steroids, or modified amino acids. They function as messengers traveling through the bloodstream to target tissues and organs, where they bind to surface... 

Glycoprotein hormones composed of two dissimilar peptides. The a-chains are similar in structure or identical the p-chains differ among hormones and confer specificity. 

Cells that produce peptide, protein, or glycoprotein hormones are derived embryologically from the entoderm or ectoblast (progenitor of ectoderm and neuroectoderm). More than 40 hormones have been identified, containing from three to over 200 amino acid residues. Table 30-2 lists the important hormones and hormonal candidates, number of amino acid residues, and sites of synthesis. 

Anterior pituitary hormones are classihed into three families the somatomammotropin family (GH and PRL), the glycoprotein hormones (LH, FSH, and TSH), and the opiomelanocortin family (ACTH, /i-endorphin, and related peptides). These three families appear to have evolved from three separate ancestral polypeptides homologous members of each family occur in other parts of the body. For example, human placental lactogen (hPL) is somatomammotropic, human chorionic gonadotrophin (hCG) is a glycoprotein hormone, and the brain and gut produce substances related to endorphins (enkephalins and dynorphin). 

The clearance of released hormone from the circulation is critical for the regulation of hormone concentration. The rate of clearance may vary from a few minutes for polypeptide hormones, to a few hours for steroid and glycoprotein hormones, to days for thyroid hormones. The peptide hormones are cleared from the circulation mostly by proteolytic mechanisms in lysosomes after their uptake by cells through binding to cell-surface receptors and nonreceptor hormone-binding sites. Steroid hormones are bound to carrier proteins in the blood as mentioned above. Binding to... 

Studies on the sub-units of human glycoprotein hormones in relation to reproduction have been reviewed. " One volume of a treatise on hormonal proteins and peptides has been devoted to thyroid hormones. The ectopic production of human chorionic gonadotrophin (hCG) and its a- and /J-sub-units has been discussed. ... 

The reaction of l-ethyl-3(3-dimethylaminopropyl)carbodi-imide with bovine lutrophin has been studied and the reaction conditions have been investigated. Spectrophotometric measurements, tryptic peptide maps, and sodium dodecyl sulphate-urea polyacrylamide gel electrophoresis banding patterns were obtained and compared for native and cross-linked derivatives of the glycoprotein hormone. ... 

---