Chlorophyll b is synthesized from chlorophyll a by the oxidation of the methyl group on the ring B of the tetrapyrrole ring to the formyl group. Previously, we reported that chlorophyllide b could be converted to chlorophyll a in isolated cucumber etioplasts indicating the conversion of chlorophyll b to chlorophyll a. To identify the intermediate molecule, we used barley etioplasts instead of cucumber. Chlorophyll a and an additional pigment were found after incubation of chlorophyllide b with isolated barley etioplasts. The pigment has the same retention time and absorption spectrum as 7-hydroxymethyl chlorophyll, which has the hydroxymethyl group on ring B instead of the formyl group of chlorophyll b. Authentic 7-hydroxymethyl chlorophyll was prepared by reduction of chlorophyll b by NaBH. Chlorophyll a accumulated during the incubation of 7-hydroxymethyl chlorophyllide with etioplasts. These findings indicate that chlorophyll b is converted to chlorophyll a via 7-hydroxymethyl chlorophyll. Chlorophyll b and 7-hydroxymethyl chlorophyll accumulated within a short period of incubation of chlorophyllide b with etioplasts. However, chlorophyll a accumulated with a concomitant decrease of chlorophyll b and 7-hydroxymethyl chlorophyll. These observations also suggest that chlorophyll b is converted to 7-hydroxymethyl chlorophyll and then to chlorophyll a. Both steps required ATP.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				Y. Horie, H. Ito, M. Kusaba, R. Tanaka, and A. Tanaka Participation of Chlorophyll b Reductase in the Initial Step of the Degradation of Light-harvesting Chlorophyll a/b-Protein Complexes in Arabidopsis J. Biol. Chem., June 26, 2009; 284(26): 17449 - 17456. [Abstract] [Full Text] [PDF]

				C. Reinbothe, H. Satoh, J.-P. Alcaraz, and S. Reinbothe A Novel Role of Water-Soluble Chlorophyll Proteins in the Transitory Storage of Chorophyllide Plant Physiology, April 1, 2004; 134(4): 1355 - 1365. [Abstract] [Full Text] [PDF]

				R. Tanaka, M. Hirashima, S. Satoh, and A. Tanaka The Arabidopsis-accelerated cell death Gene ACD1 is Involved in Oxygenation of Pheophorbide a: Inhibition of the Pheophorbide a Oxygenase Activity does not Lead to the "Stay-Green" Phenotype in Arabidopsis Plant Cell Physiol., December 15, 2003; 44(12): 1266 - 1274. [Abstract] [Full Text] [PDF]

				V. L. Kolossov and C. A. Rebeiz Chloroplast Biogenesis 88: PROTOCHLOROPHYLLIDE b OCCURS IN GREEN BUT NOT IN ETIOLATED PLANTS J. Biol. Chem., December 12, 2003; 278(50): 49675 - 49678. [Abstract] [Full Text] [PDF]

				A. Pruzinska, G. Tanner, I. Anders, M. Roca, and S. Hortensteiner Chlorophyll breakdown: Pheophorbide a oxygenase is a Rieske-type iron-sulfur protein, encoded by the accelerated cell death 1 gene PNAS, December 9, 2003; 100(25): 15259 - 15264. [Abstract] [Full Text] [PDF]

				S. Reinbothe, S. Pollmann, and C. Reinbothe In Situ Conversion of Protochlorophyllide b to Protochlorophyllide a in Barley. EVIDENCE FOR A NOVEL ROLE OF 7-FORMYL REDUCTASE IN THE PROLAMELLAR BODY OF ETIOPLASTS J. Biol. Chem., January 3, 2003; 278(2): 800 - 806. [Abstract] [Full Text] [PDF]

				H. Xu, D. Vavilin, and W. Vermaas The Presence of Chlorophyll b in Synechocystis sp. PCC 6803 Disturbs Tetrapyrrole Biosynthesis and Enhances Chlorophyll Degradation J. Biol. Chem., November 1, 2002; 277(45): 42726 - 42732. [Abstract] [Full Text] [PDF]

				S. Hortensteiner and U. Feller Nitrogen metabolism and remobilization during senescence J. Exp. Bot., April 15, 2002; 53(370): 927 - 937. [Abstract] [Full Text] [PDF]

				P. Folly and N. Engel Chlorophyll b to Chlorophyll a Conversion Precedes Chlorophyll Degradation in Hordeum vulgare L. J. Biol. Chem., July 30, 1999; 274(31): 21811 - 21816. [Abstract] [Full Text] [PDF]

				V. Scheumann, S. Schoch, and W. Rudiger Chlorophyll a Formation in the Chlorophyll b Reductase Reaction Requires Reduced Ferredoxin J. Biol. Chem., December 25, 1998; 273(52): 35102 - 35108. [Abstract] [Full Text] [PDF]

				A. Tanaka, H. Ito, R. Tanaka, N. K. Tanaka, K. Yoshida, and K. Okada Chlorophyll a oxygenase (CAO) is involved in chlorophyll b formation from chlorophyll a PNAS, October 13, 1998; 95(21): 12719 - 12723. [Abstract] [Full Text] [PDF]

				S. Satoh, M. Ikeuchi, M. Mimuro, and A. Tanaka Chlorophyll b Expressed in Cyanobacteria Functions as a Light-harvesting Antenna in Photosystem I through Flexibility of the Proteins J. Biol. Chem., February 2, 2001; 276(6): 4293 - 4297. [Abstract] [Full Text] [PDF]