Fig. 5

Detection of hsTRAIL protein production and secretion by L. lactis (hsTRAIL+). a hsTRAIL was detected in supernatants from broth cultures of L. lactis (hsTRAIL+) by Western blot and appeared in two bands indicating 160 aa (122–281) hsTRAIL molecule without usp45 leader peptide and devoids of 9 amino acids from N-terminus (upper band) and more truncated hsTRAIL ligand with 132 aa (150–281; lower band). Secretion of hsTRAIL started within the first hour after beginning of the induction with nisin (25 ng/ml). M—molecular weight marker; rhTRAIL (PeproTech, London, UK)—recombinant human TRAIL used as positive control; NC—protein sample precipitated from supernatant of L. lactis (hsTRAIL−) culture used as the negative control. Data from one representative experiment out of five performed are shown. b Concentrated supernatants of broth culture of L. lactis (hsTRAIL±) bacteria or precipitated proteins from supernatants were subjected to SDS-PAGE electrophoresis and SYPRO^® Ruby Protein Gel staining. M—marker; “-”—blank space; Sup.—supernatant; rhTRAIL—recombinant human TRAIL used as positive control; A—hsTRAIL “upper”; B—hsTRAIL “lower” band; PREP.—precipitation using chloroform–methanol method. Data from one representative experiment out of three performed are shown