PURIFICATION OF HIGHLY INTACT PLASTIDS FROM VARIOUS HETEROTROPHIC PLANT-TISSUES - ANALYSIS OF ENZYMATIC EQUIPMENT AND PRECURSOR DEPENDENCY FOR STARCH BIOSYNTHESIS

Autor(en): NEUHAUS, HE
BATZ, O
THOM, E
SCHEIBE, R 
Stichwörter: AMYLOPLASTS; Biochemistry & Molecular Biology; CAPACITIES; CARBOHYDRATE-METABOLISM; CELLS; CHLOROPLAST; ENDOSPERM; GLUCOSE-6-PHOSPHATE; MALATE-DEHYDROGENASE; PISUM-SATIVUM; SPINACH LEAVES
Erscheinungsdatum: 1993
Herausgeber: PORTLAND PRESS LTD
Journal: BIOCHEMICAL JOURNAL
Volumen: 296
Ausgabe: 2
Startseite: 395
Seitenende: 401
Zusammenfassung: 
Starting with a protocol originally developed for the purification of intact plastids from cauliflower buds [Journet and Douce (1985) Plant Physiol. 79, 458-467] we have modified this method to obtain intact heterotrophic plastids from etiolated barley leaves (Hordeum vulgare) and pea (Pisum sativum) and maize (Zea mays) endosperm. Two subsequent centrifugation steps on Percoll gradients were performed, the first as an isopycnic, the second as zonal, centrifugation step in a swing-out rotor. Percoll density and centrifugation time were adjusted for the various tissues. The obtained plastid preparations are characterized by a low degree of contamination with other cellular components and an intactness of at least 90%. In isolated maize endosperm amyloplasts, starch synthesis is driven by exogenously applied hexose phosphates (glucose 6-phosphate and glucose 1-phosphate) rather than by dihydroxyacetone phosphate. The hexose-phosphate-dependent starch synthesis is strictly dependent upon the intactness of the plastids and is increased up to 9-fold when ATP and 3-phosphoglyceric acid are added to the incubation medium. The occurrence of fructose-1,6-bisphosphatase and malate dehydrogenases in some plastid types is discussed in relation to their possible role in starch synthesis.
ISSN: 02646021
DOI: 10.1042/bj2960395

Show full item record

Page view(s)

1
Last Week
0
Last month
1
checked on Feb 26, 2024

Google ScholarTM

Check

Altmetric