Cystathionine β-synthase: Difference between revisions
Jan Hamalcik (talk | contribs) No edit summary |
Jan Hamalcik (talk | contribs) No edit summary |
||
| Line 42: | Line 42: | ||
The type of reaction mechanisms used by the CBS is known as a double displacement or ping-pong mechanism. The rate determining step in the reaction is hydrolysis of the external aldimine of cystathionine (5). | The type of reaction mechanisms used by the CBS is known as a double displacement or ping-pong mechanism. The rate determining step in the reaction is hydrolysis of the external aldimine of cystathionine (5). | ||
[[Image:Reactions catalyzed by CBS.png|600px|left Reactions catalyzed by CBS. (A) Canonical reaction of CBS. (B) CBS reactions that generate or utilize H2S.]] | [[Image:Reactions catalyzed by CBS.png|600px|left Reactions catalyzed by CBS. (A) Canonical reaction of CBS. (B) CBS reactions that generate or utilize H2S.]] | ||
[[Image:Proposed enzymatic mechanism for the CBS.png|600px|left Proposed enzymatic mechanism for the CBS reaction with absorption maxima. Possible quinonoid intermediates between E-serine (E-PLP-L-ser) and E-aminoacrylate (E-PLPaa) or between E-aminoacrylate and E-cystathionine are not shown. The growing consensus among those working on fold type-II PLP-dependent enzymes is that the ring nitrogen does not undergo protonation during the catalytic cycle in these enzymes. However, at pH 6.5 the expectation is that the ring nitrogen is protonated as shown.]] | |||
== Disease == | == Disease == | ||