Actions of lipoxidase on arterial pressure. II. On the fractionation of soybean proteins

Abstract

We llave previously denionstrated the hypotensive effect of soybean lipoxidase preparates. However, as we progressed in our work, it became evident that differents lots of our ma­ nufacture and samples of lipoxidase of others laboratorios exhibited this activity in different degree. There was also evidence that the soybean fraction we had been using all along contained several proteins.

On chromatographying the «soybean lipoxidase» with DEAE-Cellulose we have been able to obtain several proteic fractions with different biological activities. As far as we know, this is the first time that such technique has been usedfor fractionation of this prepárate.

In figures 2 and 3 we show the obtention of the fractions and the paper electrophoresis of each one of them.

One of the new fractions obtained (f. 1) has the peroxidasic, red cell aglutinating and some of the antiadrenalinic activity, but lacks anti-hypertensine and hypotensive activities.

Another one of this fractions (f. 2) is highly specific for lipoxidasic activity and showed little hypotensive activity.

Finally, other fractions (f. 4) carry the bulk of anti-hyper­ tensine and hypotensive activities with little or no lipoxidasic activity.

We leave most of the discussion for next paper (13) whcre the hypotensive activity of the original producís is compared with that of the various fractions. We like to advance here that on the light of this new findings, the hypotensive activity does not seem to depend on a peroxidasic effect, it would rather be identified with a proteic fraction that appa- rently inhibits the hypertensive polypeptide through a more direct mechanism.

The fact that this activity is not mediatcd by peroxidation could already be hinted from the observation that catalase does not interfere with the inmediate appearence of hypoten- sion, because in other studies we had seen that, usually, cata- lase interferes with processes that depend on the formation of peroxides.