Exp Mol Med.
1998 Sep;30(3):131-135.
A variant of ornithine aminotransferase from mouse small intestine
- Affiliations
-
- 1Dental School, Chonbuk National University, Chonju, Korea.
Abstract
- The ornithine aminotransferase (OAT) activity of mouse was found to be highest
in the small intestine. The mitochondrial OAT from mouse small intestine was
purified to homogeneity by the procedures including heart treatment, ammonium
sulfate fractionation, octyl-Sepharose chromatography, and Sephadex G-150 gel
filtration. Comparing to the amino acid sequence of mouse hepatic OAT, six
N-terminal amino acid residues have been deleted in intestinal OAT. However, the
subsequent sequence was identical with that of hepatic OAT. The molecular
weights of both intestinal and hepatic OAT were estimated as 46 kDa by SDS-gel
electrophoresis and as 92 kDa by gel filtration, indicating that both native
OATs are dimeric. Biochemical properties of intestinal OAT, such as molecular
weight, pH optimum and K(m) values for L-ornithine and alpha-ketoglutarate, were
similar to those of hepatic OAT. However, intestinal OAT was more labile than
hepatic OAT to tryptic digestion.