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.
Kuboniwa
M
M
Department of Preventive Dentistry, Osaka University Faculty of Dentistry, Japan.
Amano
A
A
Shizukuishi
S
S
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