Processing and secretion of human growth hormone with an artificial signal sequence

We examined the secretion of human growth hormone in yeast cells with the artificial signal sequence L8LP, which is functional for human lysozyme secretion. The precursor was cleaved efficiently and the mature protein was secreted into the periplasmic space, but the protein aggregated. These results suggest that L8LP is also functional for human growth hormone. pI precipitation might be responsible for the aggregation.