Smalley JW, Birss AJ, Szmigielski B, Potempa J. Mechanism of methaemoglobin breakdown by the lysine-specific gingipain of the periodontal pathogen Porphyromonas gingivalis.
Biol Chem 2008;
389:1235-8. [PMID:
18713010 DOI:
10.1515/bc.2008.140]
[Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract The R- and K-gingipain proteases of Porphyromonas gingivalis are involved in proteolysis of haemoglobin from which the defensive dimeric haem pigment is formed. Whilst oxyhaemoglobin is refractory towards K-gingipain, methaemoglobin is rapidly degraded. Ligation of methaemoglobin with N3-, which effectively blocks haem dissociation from the protein, prevented haemoglobin breakdown. Haem-free globin was rapidly degraded by K-gingipain. These data emphasise the need for haemoglobin oxidation which encourages haem dissociation and makes the haem-free globin susceptible to proteolytic attack.
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