Identification of a plasminogen-binding motif in PAM, a bacterial surface protein.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Surface-associated plasmin(ogen) may contribute to the invasive properties of various cells. Analysis of plasmin(ogen)-binding surface proteins is therefore of interest. The N-terminal variable regions of M-like (ML) proteins from five different group A streptococcal serotypes (33, 41, 52, 53 and 56) exhibiting the plasminogen-binding phenotype were cloned and expressed in Escherichia coli. The recombinant proteins all bound plasminogen with high affinity. The binding involved the kringle domains of plasminogen and was blocked by a lysine analogue, 6-aminohexanoic acid, indicating that lysine residues in the M-like proteins participate in the interaction. Sequence analysis revealed that the proteins contain common 13-16-amino-acid tandem repeats, each with a single central lysine residue. Experiments with fusion proteins and a 30-amino-acid synthetic peptide demonstrated that these repeats harbour the major plasminogen-binding site in the ML53 protein, as well as a binding site for the tissue-type plasminogen activator. Replacement of the lysine in the first repeat with alanine reduced the plasminogen-binding capacity of the ML53 protein by 80%. The results precisely localize the binding domain in a plasminogen surface receptor, thereby providing a unique ligand for the analysis of interactions between kringles and proteins with internal kringle-binding determinants.

Detaljer

Författare
  • AC Wistedt
  • Ulrika Ringdahl
  • W Muller-Esterl
  • Ulf Sjöbring
Enheter & grupper
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Mikrobiologi inom det medicinska området
  • Immunologi inom det medicinska området
Originalspråkengelska
Sidor (från-till)569-578
TidskriftMolecular Microbiology
Volym18
Utgåva nummer3
StatusPublished - 1995
PublikationskategoriForskning
Peer review utfördJa