Probing the self-assembly and the accompanying structural changes of hydrophobin SC3 on a hydrophobic surface by mass spectrometry.
The fungal class I hydrophobin SC3 self-assembles into an amphipathic membrane at hydrophilic-hydrophobic interfaces such as the water-air and water-Teflon interface. During self-assembly, the water-soluble state of SC3 proceeds via the intermediate alpha-helical state to the stable end form called the beta-sheet state. Self-assembly of the hydrophobin at the Teflon surface is arrested in the alpha-helical state. The beta-sheet state can be induced at elevated temperature in the presence of detergent. The structural changes of SC3 were monitored by various mass spectrometry techniques. We show that the so-called second loop of SC3 (C39-S72) has a high affinity for Teflon. Binding of this part of SC3 to Teflon was accompanied by the formation of alpha-helical structure and resulted in low solvent accessibility. The solvent-protected region of the second loop extended upon conversion to the beta-sheet state. In contrast, the C-terminal part of SC3 became more exposed to the solvent. The results indicate that the second loop of class I hydrophobins plays a pivotal role in self-assembly at the hydrophilic-hydrophobic interface. Of interest, this loop is much smaller in case of class II hydrophobins, which may explain the differences in their assembly.
Wang
X
X
Department of Biochemistry and Mass Spectrometry Core Facility, University of Groningen, Groningen, The Netherlands.
Permentier
H P
HP
Rink
R
R
Kruijtzer
J A W
JA
Liskamp
R M J
RM
Wösten
H A B
HA
Poolman
B
B
Robillard
G T
GT
D000388:Air; D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003902:Detergents / Q000494:pharmacology; D010450:Endopeptidases / Q000494:pharmacology; D005561:Formates / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry*; D007700:Kinetics; D013058:Mass Spectrometry / Q000379:methods*; D008666:Metalloendopeptidases; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism; D010434:Pepsin A / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry; D011138:Polytetrafluoroethylene / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature; D013997:Time Factors; D014867:Water
D003902:Detergents; D005561:Formates; D005656:Fungal Proteins; D010455:Peptides; D014867:Water; C008817:peroxyformic acid; D011138:Polytetrafluoroethylene; D010450:Endopeptidases; D010434:Pepsin A; D008666:Metalloendopeptidases; C058921:endoproteinase Asp-N; D010100:Oxygen