|Schmelz, Eva - DEPT BIOCHEM, EMORY UNIV|
|Dombrink Kurtzman, Mary Ann|
|Merrill Jr, Alfred - DEPT BIOCHEM, EMORY UNIV|
Submitted to: Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: April 18, 1996
Publication Date: N/A
Technical Abstract: Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium moniliforme and a number of other fungi found on corn. FB1 is a potent inhibitor of ceramide synthase, resulting in an elevation of free sphinganine in cells. Since the removal of the tricarballylic sidechains reduces the inhibition of ceramide synthase in vitro, and Shephard et al (Fd. Chem. Toxic. 32:23-29, 1994) have found partly hydrolysed FB1 in feces, we looked at the toxicity of both intact and hydrolysed FB1 (aminopentol) on HT29 cells, a human colon carcinoma cell line. Aminopentol resulted in significant reduction in cell number only at the highest concentration used (50 uM), whereas, the same reduction was achieved with only 10 uM FB1. In accordance with the observed toxicity on cells, 50 uM FB1 caused a 10-fold greater increase in free sphinganine than was observed with the same concentration of aminopentol. The effect of both forms on the sphingolipid synthesis is highly dependent on cell density.