The influence of hydrochloric acid on the combination of oxygen with the hemocyanin of limulus polyphemus

✍ Scribed by Redfield, Alfred C. ;Mason, Eleanor D. ;Ingalls, Elizabeth N.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1932
• Tongue: English
• Weight: 989 KB
• Volume: 1
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030010109

✦ Synopsis

On the addition of hydrochloric acid to the hemocyanin of the horseshoe crab, Limulus polyphenius, the solution becomes colorless and loses its capacity to combine with oxygen (Redfield and Mason, '28). This phenonemon has been studied in some detail in the expectation that it might throw additional light upon the influence of hydrogen-ion activity on the equilibrium of oxygen with the hemocyanins and with hemoglobin.

When dilute hydrochloric acid is added to the serum of Limulus or to solutions of the heniocyanin containing electrolytes, the protein is precipitated as the isoelectric point is approached, and fails to redissolve on the further addition of acid. When preparations of Limulus hemocyanin free from salt are employed, precipitation also occurs at reactions near the isoelectric point. This precipitate redissolves when further addition of acid (equivalent to about 10 X 10-j mols HCI per gram hemocyanin) brings the reaction to approximately pH 4.5. Such solutions are of a blue color of about the same density as similar dilutions of hemocyanin in alkaline solution. On addition of larger amounts of acid, the blue color becomes less and less intense. The solutions appear 'The experimental part of this investigation was done in the laboratory of the Department of Physiology of the Harvard Medical School.