THE AMINO ACID DECARBOXYLASE OF SALIVARY SEDIMENT

¹ Department of Chemistry, Northwestern University Dental School, Chicago, Ill.

1. The presence of five amino acid decarboxylases was detected in washed suspensions of the sediment from incubated saliva: arginine, ornithine, glutamic acid, histidine, and lysine were acted on.

2. The optimal pH for decarboxylation of these amino acids was about 6.5.

3. A reproducible analytical procedure is described whereby saliva samples may be assayed for their amino acid decarboxylating activity.

4. In a study of the saliva from 50 normal subjects and 50 periodontal patients, the periodontal group showed a statistically significant higher decarboxylating activity for each of the five amino acids tested.

5. It was found that relative activities toward each of the amino acids were similar in all samples, from normal and periodontal saliva. Arginine, ornithine, glutamic acid, histidine, and lysine accounted for about 28, 51, 8, 7, and 5 per cent, respectively, of the CO₂ evolved.