Inhibition of the Hill Reaction by Tris and Restoration by Electron Donation to Photosystem II.

نویسندگان

  • T Yamashita
  • W L Butler
چکیده

Experiments in which chloroplasts were washed with tris and tricine buffers at different pH's indicated that the non-protonated (uncharged) form of tris was inhibitory to the Hill reaction while the protonated form of tris and the zwitterionic forms of tricine were non-inhibitory. Buffers analogous to tris and tricine gave similar results. Photoreduction of NADP could be restored to the inhibited chloroplasts by adding the reduced forms of p-hydroquinone, p-aminophenol, p-phenylenediamine, benzidine, semicarbazide, and dihydroxydiphenyl, all of which donated electrons to photosystem II. Photoreduction of ferricyanide was shown with those donor systems (benzidine and semicarbazide) which did not react chemically with ferricyanide. Photophosphorylation was also restored with all of the electron donors except semicarbazide.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Inhibition of Photosystem II in Isolated Chloroplasts by Lead.

Inhibition of photosynthetic electron transport in isolated chloroplasts by lead salts has been demonstrated. Photosystem I activity, as measured by electron transfer from dichlorophenol indophenol to methylviologen, was not reduced by such treatment. However, photosystem II was inhibited by lead salts when electron flow was measured from water to methylviologen and Hill reaction or by chloroph...

متن کامل

Photoreduction and Photophosphorylation with Tris - Washed Chloroplastst

The artificial electron donor compounds p-phenylenediamine (PD). N, N, N', N'tetramethyl-p-phenylenediamine (TMPD), and 2,6-dichlorophenol-indophenol (DCPIP) restored the Hill reaction and photophosphorylation in chloroplasts that had been inhibited by washing with 0.8 M tris (hydroxymethyl)aminomethane (tris) buffer, pH 8.0. The tris-wash treatment inhibited the electron transport chain betwee...

متن کامل

Inhibition of electron transport on the oxygen-evolving side of photosystem II by an antiserum to a polypeptide isolated from the thylakoid membrane.

A polypeptide fraction with the apparent molecular weight 11 000 was isolated from stroma-freed chloroplasts from Anthirrhinum majus. An antiserum to this polypeptide fraction inhibits photosynthetic electron transport in chloroplasts from Nicotiana tabacum. The relative degree of inhibition is pH dependent and has its maximum at pH 7.4. The maximal inhibition observed was 93%. The dependence o...

متن کامل

Inhibitory Effect of Crown Compound on Photoelectron Transport Activity of Beet Spinach Thylakoid Membranes

The effect o f K-picrate-18-crown-6 (crown) on the photoelectron transport activity o f beet spinach thylakoid membranes was investigated. Addition o f micromolar concentration o f crown to thylakoid preparation inhibited p-benzoquinone, chloride-indophenol, methyl viologen supported Hill activities maximally by 75 per cent in a concentration dependent manner. However, the photosystem I catalyz...

متن کامل

Fluorescence and delayed light emission in Tris-washed chloroplasts.

Yamashita and Butler [I] have shown that extraction of chloroplasts with a high concentration of Tris (0.8 M, pH 8.0) eliminates flow of electrons from water to nicotinamide adenine dinucleotide phosphate (NADP+)* or other Hill oxidants. They suggest that washing with Tris causes a block on the water side of the electron transport chain. Addition of electron donors such as reduced phenylene dia...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Plant physiology

دوره 44 3  شماره 

صفحات  -

تاریخ انتشار 1969