منابع مشابه
Water proton relaxation as a monitor of membrane-bound manganese in spinach chloroplasts.
First measurements of proton relaxation on chloroplast membranes are presented here. Experiments show that the water proton spin-lattice relaxation rate in chloroplast thylakoid membrane suspensions can be used to monitor membrane-bound manganese. The relaxation effect is reduced to 0.4 of its original value upon manganese extraction by washing with either alkaline Tris buffer or NH2OH/EDTA sol...
متن کاملCooperativity among manganese-binding sites in the H+-ATPase of chloroplasts.
Coupling factor, isolated from lettuce chloroplasts, contained several binding sites for Mn2+ ions. Three of these sites showed strong cooperative interactions having a Hill coefficient of 2.9 +/- 0.20 and a Kd of 14.7 +/- 0.44 microM. Three additional non-interacting Mn2+-binding sites were found with a Kd of 46.7 +/- 2.3 microM. Chemical modification with naphthylglyoxal of 1 arginyl residue/...
متن کاملNuclear magnetic relaxation by the manganese in aqueous suspensions of chloroplasts.
Proton and oxygen-17 NMR relaxation rate (T1-1 and T2-1) data are presented for aqueous suspensions of dark-adapted chloroplasts. It is concluded from the dependence of the proton relaxation rates (PRR) upon Mn concentration that T1-1 and T2-1 are determined largely by the loosely bound Mn present in the chloroplast membranes. The frequency and temperature dependences of PRR are characteristic ...
متن کاملFreeze-fracture ultrastructure of thylakoid membranes in chloroplasts from manganese-deficient plants.
Leaves from spinach (Spinacia oleracea L. cv Hybrid 102) plants grown in Mn-deficient nutrient solution were characterized by chlorosis, lowered chlorophyll a/b ratio and reduced electron transport. There were characteristic changes in room temperature fluorescence induction kinetics with increased initial yield (F(o)) and decreased variable fluorescence (F(v)). The fluorescence yield after the...
متن کاملThe Effect of Manganese Deficiency on the Structure of Spinach Chloroplasts
Manganese is involved in the photosynthetic reactions of algae and leaves of higher plants (1-3). In tomato, manganese deficiency results in chloroplasts with a greatly reduced Hill reaction activity per unit chlorophyll (3). In spinach, manganese deficiency causes a 50 to 70 per cent reduction in the FMN-mediated photophosphorylation of isolated chloroplasts but only slightly affects the phosp...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1970
ISSN: 0306-3283
DOI: 10.1042/bj1160040pa