title: Differential distribution of chlorophyll biosynthetic intermediates in stroma, envelope and thylakoid membranes in Beta vulgaris.
abstract: Stroma, envelope and thylakoid membranes were prepared from chloroplasts isolated from leaves of Beta vulgaris. Out of total plastidic protochlorophyllide, envelope membranes contained 1.5%, thylakoids had the maximum 98.48% and stroma had a trace fraction of 0.02%. Distribution of the Mg-protoporphyrin IX and its monoester was 89.0% in thylakoids, 10.0% in stroma and 1.0% in envelope. A substantial fraction (33.77%) of plastidic protoporphyrin IX was partitioned into stroma. Envelope contained 0.66% and thylakoids had 65.57% of the total plastidic protoporphyrin IX pool. The proportion of monovinyl and divinyl forms of protochlorophyllide was almost similar in intact plastid, thylakoids, and outer and inner envelope membranes suggesting a tight regulation of vinyl reductase enzyme. The significance of differential distribution of chlorophyll biosynthetic intermediates among thylakoids, envelope and stroma is discussed.
authors.affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
authors.forename: Anasuya
authors.initials: A
authors.lastname: Mohapatra
authors.forename: Baishnab C
authors.initials: BC
authors.lastname: Tripathy
mesh_terms: D027461:Beta vulgaris / Q000378:metabolism*; D002734:Chlorophyll / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D011521:Protochlorophyllide / Q000737:chemistry / Q000378:metabolism; D020524:Thylakoids / Q000378:metabolism*
chemical_list: D002734:Chlorophyll; D011521:Protochlorophyllide