Stop-transfer function of pseudo-random amino acid segments during translocation across prokaryotic and eukaryotic membranes.
We have measured the efficiency of stop-transfer function for a set of pseudo-random, 18-residue amino acid segments, both in Escherichia coli and in mammalian microsomes. In general, stop-transfer function correlates well with the mean hydrophobicity of the segment, though exceptions exist. Kinetic studies suggest that polar segments are rapidly translocated through the E. coli inner membrane and that strongly hydrophobic segments become permanently anchored, while sequences with an intermediate mean hydrophobicity become partly trapped in a transmembrane disposition for a considerable time before being released to the periplasm or degraded.
Sääf
A
A
Department of Biochemistry, Stockholm University, Sweden.
Wallin
E
E
von Heijne
G
G
D000469:Alkaline Phosphatase / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002462:Cell Membrane / Q000378:metabolism*; D017931:DNA Primers; D004926:Escherichia coli / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism*; D008322:Mammals; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012156:Reticulocytes / Q000378:metabolism; D014158:Transcription, Genetic
D017931:DNA Primers; D008565:Membrane Proteins; D011994:Recombinant Proteins; D000469:Alkaline Phosphatase