Identification of Hemin-binding Protein of Oral Streptococci via Electrophoresis in SDS Polyacrylamide Gel

Background and Objectives: It has been reported that hemin binding proteins are involved in the mechanism of obtaining iron in some bacteria. Oral streptococci in the dental plaque are assumed to acquire iron through hemin or hemin compounds. The aim of this study was to identify the presence of a protein (hemin binding protein) involved in the hemin binding mechanism of oral streptococci.

Methodology: In this study, we investigated the presence of proteins involved in hemin binding of oral streptococci through sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis using hemin-agarose beads.

Results: As a result of SDS-PAGE analysis, similar or different sizes of hemin binding protein bands were observed depending on the strains belonging to streptococci. The molecular weight of hemin binding protein in Streptococcus gordonii, Streptococcus rattus, Streptococcus sobrinus, Streptococcus sanguis and Streptococcus oralis were approximately 95 kDa, 43 kDa, 43 kDa, 39 kDa, and 39 kDa, respectively.

Conclusion: In this study, the presence of hemin binding protein in streptococci was confirmed and the proteins involved in hemin binding in different species of oral streptococci may be different.