Proteins of timothy and orchard grass pollen and their reaction to vernal hay fever

Abstract

The most widely accepted view regarding the causation of hay fever is that it is due to the pollen of certain grasses and weeds blooming in the summer and fall. Dunbar and his pupils showed convincingly that the proteins of the pollens are responsible for hay fever. There have been several attempts in the past to obtain the active constituent, but a complete, systematic chemical investigation has never been carried out. The most comprehensive study was made by Heyl 1 on ragweed. Unfortunately, however, the clinical part of his investigation was not carried out to completion.

The material used for our study consisted of the pollen of timothy and orchard grass. On account of the meager supply available, we can report only on a qualitative study.

For the exhaustive extraction, we used 5 gm. of each of the pollens, and extracted them successively with 10 per cent sodium chloride, 0.5 per cent sodium hydroxide, and 70 per cent alcohol. It is remarkable how large a percentage of the extracted nitrogen is non-protein nitrogen. From half to one-third of the total nitrogen of the pollen is not extractable with these solvents.

In the preparation study, we used about 75 gm. of the pollen, which had been previously extracted with ether to remove fatty material. It was first extracted with water, and then with 10 per cent NaCl until there was practically no nitrogen found in the extract. The residue was extracted with alcohol, and finally with 0.2 per cent sodium hydroxide. Coagulation tests made on both the water and salt extracts of the timothy pollen indicated the presence of two proteins, one coagulating at 68.8° C., and the other at 85° C. Similar extracts of the orchard grass pollen also showed the presence of two proteins, one coagulating at 65° and another at 85.2° C.