Pepsin D. A minor component of commercial pepsin preparations

Methods are described for the isolation and purification of pepsin D, an enzyme which accounts for about 10% of the enzymic activity in commercial preparations of pepsin. Pepsin D is similar to pepsin in having a molecular weight of about 35000, the same C-terminal amino acid sequence, and an N-terminal isoleucine residue. It differs in having no phosphate residue. Pepsin D is similar to pepsin in its ability to digest haemoglobin, acetyl-l-phenylalanyl-l-di-iodotyrosine and gelatin but it is twice as active as pepsin in the clotting of milk. It has the same specificity as pepsin in its action on the B-chain of oxidized insulin. It is probable that the pepsin D in commercial preparations of pepsin arises from the activation of gastric pepsinogen D.

Pepsinogen D. A fourth proteolytic zymogen from pig gastric mucosa

Methods are described for the isolation and purification of pepsinogen D, a minor zymogen occurring to the extent of about 5% of the potential proteolytic activity in neutral extracts of the pig gastric mucosa. The physical and chemical properties of this zymogen indicate that it is very similar to, if not identical with, dephosphopepsinogen.

Life stress and lymphocyte alterations among patients with rheumatoid arthritis

The relation between life stress and immune parameters was investigated for 33 female rheumatoid arthritis (RA) patients interviewed during three routine monthly clinic checkups. Life stress from major and minor events, coping efficacy, and self-reported psychological distress were assessed, and immunofluorescence of T-cells and B-cells was performed on the blood drawn during each visit. Small stressful events were positively related to the proportion of circulating B-cells, psychological distress was inversely related to proportion of circulating T-cells, and major life events were associated with lower T-helper/T-suppressor cell ratios.