Fractionation of Phytohemagglutinin, I. Purification of the Rna and Dna Synthesis-Stimulating Substances and Evidence That They Are Not Proteins

Abstract

Abstract.-We have separated the RNA synthesis-stimulating activity and the DNA synthesis-stimulating activity of extracts of Phaseolus vulgaris (phytohemagglutinin) from the erythroagglutinins, leukoagglutinins, and cytotoxic factors. We have shown that the substances stimulating the synthesis of nucleic acids are probably not proteins, since they are not significantly affected by rigorous deproteinization or treatment by trypsin and pronase. Likewise, they do not appear to be nucleic acids, since they are not precipitated by perchloric acid and resist RNase, DNase, and phosphodiesterases. They are probably not carbohydrates, since 98 per cent of the carbohydrate can be removed from a preparation with only a moderate loss in activity. The RNA and DNA synthesis-stimulating activities are probably associated with separate molecules, since they are destroyed by periodate at different rates.

Untersuchungen zur wachstumsfördernden Wirkung von Antiproteasen auf Lymphozyten <i>in vitro</i>

“…1). Die Antitrypsinaktivität des PHA fand sich in der ersten (PHA-Fraktion A, pH 4,5) und zweiten (PHAFraktion B, pH 6,0) Fraktion einer Chromatographie von PHA über SE-Sephadex C-50 im diskontinuierlichen pH-Gradienten nach Weber [14] und in dem nach G oldberg [3] …”

“…Nach Auftrennung von PHA über SE-Sephadex C-50 im diskontinuierlichen PHA-Gradienten nach Weber [14] wurde das Antitrypsin in der zweiten Fraktion (pH 6,0) gefunden. Auch in der nach G oldberg [3] durch Deproteinisierung mit Perchlorsäure gewonnenen Fraktion konnte Antiproteaseaktivität nachgewiesen werden. Beide Frak- tionen besassen eine deutliche lymphozytenstimulierende Wirkung.…”

Isolation of Substances That Stimulate RNA Synthesis from Red Kidney Bean: Their Activities in Lymphocytes and Escherichia coli

“…To each ml of F I, 0.16 ml of 11.5 M HCl04 was added at 00, as described (8). After 40 min at O°, the suspension was centrifuged.…”

“…1, the following purification procedure was used: Red kidney beans (Phaseolus vulgaris) were extracted for preparation of "dry powder" (15). Fraction I (F I) was prepared by extraction of 6.0 g of "dry powder" (derived from 500 g of beans) with 100 ml of PM buffer (8). The cloudy suspension was centrifuged, the precipitate was discarded, and the supernatant was filtered through a Sartorius membrane filter, pore size 0.22 um.…”

“…After the partial separation by Rivera and Mueller (7) of RNA synthesisstimulating and mitogenic activities from the leukoagglutinating activity of PHA, Goldberg et al (8) have shown that these factors are completely separable.…”