pheophorbidase [EC:3.1.1.82]

PMID:16384908

Suzuki Y, Amano T, Shioi Y

Characterization and cloning of the chlorophyll-degrading enzyme pheophorbidase from cotyledons of radish.

Plant Physiol 140:716-25 (2006)
DOI:10.1104/pp.105.071290

[ag:BAE54383]

Hydrolases;
Acting on ester bonds;
Carboxylic-ester hydrolases

pheophorbide-a hydrolase

pheophorbide a + H2O = pyropheophorbide a + methanol + CO2 (overall reaction) [RN:R08974];
(1a) pheophorbide a + H2O = C-132-carboxypyropheophorbide a + methanol [RN:R08975];
(1b) C-132-carboxypyropheophorbide a = pyropheophorbide a + CO2 (spontaneous) [RN:R08976]

R08974 R08975 R08976

pheophorbide a [CPD:C18021];
H2O [CPD:C00001];
C-132-carboxypyropheophorbide a

This enzyme forms part of the chlorophyll degradation pathway, and is found in higher plants and in algae. In higher plants it participates in de-greening processes such as fruit ripening, leaf senescence, and flowering. The enzyme exists in two forms: type 1 is induced by senescence whereas type 2 is constitutively expressed [1,2]. The enzyme is highly specific for pheophorbide as substrate (with a preference for pheophorbide a over pheophorbide b) as other chlorophyll derivatives such as protochlorophyllide a, pheophytin a and c, chlorophyll a and b, and chlorophyllide a cannot act as substrates [2]. Another enzyme, called pheophorbide demethoxycarbonylase (PDC), produces pyropheophorbide a from pheophorbide a without forming an intermediate although the precise reaction is not yet known [1].

EC 3.1.1.82 created 2007

1  [PMID:16228561]

Suzuki Y, Doi M, Shioi Y.

Two enzymatic reaction pathways in the formation of pyropheophorbide a.

Photosynth. Res. 74 (2002) 225-33.

[ag:BAE54383]

2  [PMID:16384908]

Suzuki Y, Amano T, Shioi Y.

Characterization and cloning of the chlorophyll-degrading enzyme pheophorbidase from cotyledons of radish.

Plant. Physiol. 140 (2006) 716-25.

[ag:BAE54383]

3  [PMID:16669755]

Hortensteiner S.

Chlorophyll degradation during senescence.

Annu. Rev. Plant. Biol. 57 (2006) 55-77.