Discovery of hemoglobin

During the 19th and early 20th century a number of protein crystals were observed in animal and plant cells under the light microscope.

The first description of oxygen-carrying protein hemoglobin is attributed to work on earthworm blood by F. L Hünefeld in 1840. He accidentally creates the first protein crystals of hemoglobin.

By the time Wilhelm Preyer wrote his book Blood Crystals in 1871, hemoglobin crystals from over forty species of mammals, fishes, birds and amphibians has been described.

A 1909 book entitles The Crystallography of Hemoglobins, by physiologist Edward Reichert and Thomas Brown reproduced 600 photomicrographs of hemoglobin crystals from a hundred different species. 

Physiologists and medical chemists in the late nineteenth century devoted an immense amount of research to hemoglobin. A major advanced came in 1904 when Christian Bohr, Karl Hasselbalch and August Krogh discovered the binding oxygen hemoglobin.

In 1954, Max Perutz discovers that soaking protein crystals in heavy atoms will provide information needed to turn diffraction patterns into structural pictures of proteins.

In 1959 he determined the molecular structure of myoglobin (similar to hemoglobin) by X-ray crystallography. Before that John Kendrew obtains the first high-resolution three-dimensional structure of a protein myoglobin.

This work resulted in Max Perutz sharing with John Kendrew the 1962 Nobel Prize in Chemistry.

The role of hemoglobin in the blood was elucidated by French physiologist Claude Bernard.

Other recent discovery is the role hemoglobin plays in blood pressure regulation. Hemoglobin attaches to nitric oxide gas and transports it to and from tissues. Nitric oxide produces vasodilation.
Discovery of hemoglobin