Certain N-terminal peptides inhibit uptake of mature aspartate aminotransferase by isolated mitochondria.

To gain insight into the uptake of mature aspartate aminotransferase by isolated mitochondria, the capability of certain cyanogen bromide peptides from mature beef heart mitochondrial aspartate aminotransferase to inhibit enzyme uptake was kinetically tested. N-terminal peptides (1-9 and 10-31) proved to inhibit the rate of aspartate aminotransferase uptake respectively in purely competitive and non-competitive ways, whereas other peptides distal from the N-terminus (203-217, 321-327 and 328-353) were found to be completely ineffective.