Spontaneous assembly of a self-complementary oligopeptide to form a stable macroscopic membrane.
A 16-residue peptide [(Ala-Glu-Ala-Glu-Ala-Lys-Ala-Lys)2] has a characteristic beta-sheet circular dichroism spectrum in water. Upon the addition of salt, the peptide spontaneously assembles to form a macroscopic membrane. The membrane does not dissolve in heat or in acidic or alkaline solutions, nor does it dissolve upon addition of guanidine hydrochloride, SDS/urea, or a variety of proteolytic enzymes. Scanning EM reveals a network of interwoven filaments approximately 10-20 nm in diameter. An important component of the stability is probably due to formation of complementary ionic bonds between glutamic and lysine side chains. This phenomenon may be a model for studying the insoluble peptides found in certain neurological disorders. It may also have implications for biomaterials and origin-of-life research.
Zhang
S
S
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Holmes
T
T
Lockshin
C
C
Rich
A
A
D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry; D002942:Circular Dichroism; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013373:Substance P / Q000031:analogs & derivatives / Q000737:chemistry
D000682:Amyloid; D008567:Membranes, Artificial; D009842:Oligopeptides; D010446:Peptide Fragments; D010455:Peptides; D013373:Substance P; C042867:spantide