... in humans, including insulin, insulin-like growth factor-1 and -2, relaxin-1, -2 and -3, and INSL4, -5 and -6. INSL3 was cloned in the early1990s from the cDNA library of the Leydig cells of the ... spectra of the humanINSL3 precursor before and after in vitro refolding. (B) Far-UV spec-tra of the mature human INSL3 and porcine insulin.Fig. 7. cAMP activity of recombinant INSL3 and its ... expression, asingle-chain INSL3 precursor was designed as shown in Fig. 1A,B. In this peptide, the B-chain and A-chainwere linked by an eight-residue linker sequence. Forinsulin and insulin-like...