Overview
Erythropoietin Extra credit report (699 word count) Introduction to Biochemistry Michael Prentice April 26, 2017
Erythropoietin (EPO) is naturally occurring protein hormone the body uses every day, however, its abuse
in synthetic form is a type of blood doping that has been the subject of many recent sporting fraud
cases, most notably, multiple Tour de France winner Lance Armstrong, but has also been abused in other
sporting venues, particularly the Olympic games (1).
Erythropoietin is a type I cytokine protein hormone which is created primarily in the kidney but also less
so in the liver (2). Endogenous EPO was first isolated in 1977, and its gene was first cloned in 1985.The
gene for human erythropoietin is located at chromosome 7q11-22. It is composed of four introns and
five exons, resulting in a post-transcriptional single polypeptide of 193 amino acids. This single amino
acid backbone undergoes post-translational modification whereby one O-glycosylation and three
N-glycosylation sites are added and 28 amino acids are removed. This results in the final primary
structure of mature EPO containing 165 amino acids in a polypeptide chain with a molecular mass
estimated to be 30 kilodaltons (3).
EPO primary structure (4)