Abstract:Glycerate or OH-pyruvate was converted into serine by spinach leaf peroxisomes. The rate of conversion in intact peroxisomes was about 2.5 times higher than that in broken peroxisomes, with glycine as the NH2-donor. This higher converting rate in intact peroxisomes was not due to the increase of available OH-pyruvate concentration in intact peroxisomes, or the loss of cofactors to the apoenzyme in broken peroxisomes, also not due to the effect of active transferring system of glycine in peroxisomal membrane. The results suggested that there is a glycine aminotransferase in spinach leaf peroxisomes, and the high converting rate in intact peroxisomes was probably due to the difference of conformation or configuration of the glycine aminotransferase between the intact peroxisomes and broken peroxisomes.