Isolation of Antitumor Proteins Abrin‐a and Abrin‐b From Abrus Precatorius*

Abstract

Two toxic proteins were purified from the seeds of Abrus precatorius by DEAE‐A 50 and Sepharose 4B chromatography. One of them does not bind on the Sepharose 4B column (Abrin‐b) and the other (Abrin‐a) is eluted with 0.2 M galactose. The amino acid compositions and tryptic maps of these two proteins were similar, but not identical. The molecular weights estimated by SDS‐gel electrophoresis were 67,000 for abrin‐b as compared with 65,000 for abrin‐a. In the presence of mercaptoethanol, both abrin‐a and abrin‐b gave rise to two bands.The lethal doses of abrin‐a and abrin‐b for mice recorded within 48 h were 10 and 25μg per kg of body weight respectively. Abrin‐a at 0.8 μg per ml concentration level agglutinated human 0‐type erythrocytes, whereas abrin‐b showed no such activity. Abrin‐a at 5 μg per ml concentration level agglutinated both the Sarcoma 180 cells and Ehrlich ascites tumor cells, but it required 150 μg per ml for abrin‐b. Both these two proteins at a sublethal dose could inhibit the growth of Ehrlich ascites tumor cells which were injected simultaneously with these proteins. 131I‐abrin‐a and 131I‐abrin‐b were able to bind Sarcoma 180 cells, and the binding of abrin‐a could be inhibited by lactose, raffinose, galactose and rhamnose, but none of 15 sugars tested inhibited the binding of abrin‐b.

Toxicity and Detection of Ricin and Abrin in Beverages

“…e One group of three female BALB/c mice was used as a negative control for each beverage. Accurate determination of toxin concentration in the extracts was further limited by differences in the cross-reactivities of the isozymes (7,15,17,24,27,39), as exemplified by the fivefold difference observed in the responses generated by abrin fraction II and commercially available abrin (Fig. 3).…”

Potential antifertility agents from plants: A comprehensive review

“…On the contrary, flowers are pink clustered. Compounds isolated from AP include Abrin-a & b (Lin et al, 1979), abruquinone A (Wang et al, 1995), abrusoside E (Kennelly et al, 1996), 7,5-dihydroxy-6,4 -dimethoxy isoflavone 7-O-␤-d-galactopyranoside (Saxena and Sharma, 1999) and triterpenoid saponins (Anam, 2001). The leaves and roots are sweetish and traditionally used to cure fever, stomatitis, asthma and bronchititis (Kirtikar and Basu, 1987a,b).…”

Abrin Toxicity and Bioavailability after Temperature and pH Treatment

“…Abrin isolated from Abrus precatorius seeds has many different potential isoforms [ 7 , 8 , 9 ]. Three to four isoforms have been isolated by different laboratories and reported to have different toxin activities or median lethal doses (LD 50 ) [ 7 , 9 , 10 , 11 , 12 , 13 , 14 ]. Our abrin toxin preparations also contained a 120 kDa heterotetrameric species, agglutinin (APA-1).…”