Cross-strand disulphides in cell entry proteins: poised to act.
Cross-strand disulphides (CSDs) are unusual bonds that link adjacent strands in the same beta-sheet. Their peculiarity relates to the high potential energy stored in these bonds, both as torsional energy in the highly strained disulphide linkage and as deformation energy stored in the sheet itself. CSDs are relatively rare in protein structures but are conspicuous by their presence in proteins that are involved in cell entry. The finding that entry of botulinum neurotoxin and HIV into mammalian cells involves cleavage of CSDs suggests that the activity of other cell entry proteins may likewise involve cleavage of these bonds. We examine emerging evidence of the involvement of these unusual disulphides in cell entry events.
Wouters
Merridee A
MA
Victor Chang Cardiac Research Institute, Sydney, Australia. m.wouters@victorchang.unsw.edu.au
Lau
Ken K
KK
Hogg
Philip J
PJ
D001426:Bacterial Proteins / Q000737:chemistry; D001905:Botulinum Toxins / Q000737:chemistry; D002462:Cell Membrane / Q000378:metabolism; D004220:Disulfides; D006678:HIV / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D014764:Viral Proteins / Q000737:chemistry
D001426:Bacterial Proteins; D004220:Disulfides; D014764:Viral Proteins; D001905:Botulinum Toxins