Hemoglobin-binding protein purified from Porphyromonas gingivalis is identical to lysine-specific cysteine proteinase (Lys-gingipain).
The functional protein that binds to human hemoglobin (hemoglobin-binding protein; HBP) was purified from Porphyromonas gingivalis cells. The analyses of the amino-terminal sequence and amino acid composition revealed that HBP is identical to lysine-specific cysteine proteinase (51 kDa Lys-gingipain; KGP) of P. gingivalis 381. It is a novel finding that KGP has binding affinity to hemoglobin. The binding activity of HBP was enhanced by acidic or anaerobic conditions. Arg-gingipain, a member of the gingipain family, of P. gingivalis exhibited no ability to bind to hemoglobin. The recombinant protein of KGP (r-KGP) generated in Escherichia coli showed both hemoglobin-binding and proteolytic activities. The treatment of r-KGP by protein disulfide isomerase effectively enhanced binding to hemoglobin, whereas the proteinase activity was decreased. The treated r-KGP significantly inhibited the binding of hemoglobin to the whole cell extracts in a dose-dependent manner. These results suggest that the hemoglobin binding of P. gingivalis is mediated by KGP through active domain(s) distinct from that for proteinase activity.
Department of Preventive Dentistry, Osaka University Faculty of Dentistry, Japan.
M
M
Kuboniwa
A
A
Amano
S
S
Shizukuishi
D018829:Adhesins, Bacterial / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001665:Binding Sites; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004926:Escherichia coli; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D010957:Plasmids; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
D018829:Adhesins, Bacterial; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins; D006454:Hemoglobins; D011994:Recombinant Proteins; D003546:Cysteine Endopeptidases