A1 Fraction Research Articles

Identification and separation of lysosomal carboxypeptidases

1. 1. Four distinct carboxypeptidases (EC 3.4.12.-) were shown to exist in rat liver lysosomes: cathepsin A, catheptic carboxypeptidase B, catheptic carboxypeptidase C, and catheptic carboxypeptidase G. These carboxypeptidases were distinguished on the basis of substrate specificity, thiol requirement, and separation by Sephadex G-100 column chromatography. The K m and pH optimum for each carboxypeptidase were determined. 2. 2. From the Sephadex G-100 elution profile, two peaks of cathepsin A activity were found. The major cathepsin A peak, cathepsin A1, was further purified by ion-exchange chromatography on DEAE-cellulose. 3. 3. The highly purified cathepsin A1 fraction hydrolyzed N- benzyloxycarbonyl (Cbz)-Glu-Phe, Cbz-Gly-Phe, and Ac-Phe-Tyr, which suggests that these hydrolytic activities were due to the same enzyme. 4. 4. Catheptic carboxypeptidase B and catheptic carboxypeptidase G eluted from the Sephadex G-100 column along with cathepsin B2. This suggests that cathepsin B2 may have carboxypeptidase activity. 5. 5. The purification of the lysosomal carboxypeptidases over homogenate activities was: cathepsin A1, 1280-fold; catheptic carboxypeptidase B, 220-fold; and catheptic carboxypeptidase G, 920-fold. Catheptic carboxypeptidase C was purified 16-fold over light-mitochondrial supernatant activity.

Search for prostaglandin A1 in onion.

AbstractA fatty cid fraction separated from yellow onion has been subjected to thin layer chromatographic techniques, UV and IR spectrophotometric analyses. This silicic acid‐chromatographed fraction corresponds to the prostaglandin A1 fraction. Preliminary identification strongly suggests that this component of onions appears to be a prostaglandin (PGA1) or a prostaglandin‐like compound.

Fatty Acids of Surface Lipids from Uninvolved Skin in Psoriasis

From an examination of the concept that surface lipids of uninvolved skin areas in psoriasis are deficient in esterified sterols (1), it has become evident that misleading results can be obtained if studies of this type involve “casual” surface lipids (2). We have extended our investigations to other features of lipids from these skin sites. These features have been described in recent publications as typical of psoriasis and include the following : (i) Reduced “acid number” (1, 3, 4). (ii) Reduced amounts of unsaturated fatty acids (5). (iii) Increased amounts of long-chain (C18 or over) saturated acids in the FF A1 fraction including a C acid which was 10 times more abundant than in the same fraction from control subjects (6).