Total Synthesis of the α-Subunit of Human Glycoprotein Hormones: Toward Fully Synthetic Homogeneous Human Follicle-Stimulating Hormone

Described herein is the first total chemical synthesis of the unique a-subunit of the human glycoprotein hormone (alpha-hGPH). Unlike the biologically derived glycoprotein hormones, which are isolated as highly complex mixtures of glycoforms, alpha-hGPH obtained by chemical synthesis contains discrete homogeneous glycoforms. Two such systems have been prepared. One contains the disaccharide chitobiose at the natural N-glycosylation sites. The other contains dodecamer oligosaccharides at these same sites. The dodecamer sugar is a consensus sequence incorporating the key features associated with human glycoproteins.