Chlorophyll

The Chlorophyll-Protein Complex

“…They are deep green in color and exceedingly stable, remaining apparently unaltered over a long period of time, either at the pH of the phosphate buffer (pH 7.3-7.5), or, after dialysis against distilled water, at about pH 6.0. In addition, the suspensions exhibit the physical characteristics described by other workers (5,(12)(13)(14)(15): a strong maximum absorption band at about 678 m~t, photostabflity, red fluorescence, and sensitivity to protein coagulants. On the other hand, either an increase in temperature, removal of water by drying, or freezing can denature the material.…”

“…The effect of various uni-univalent electrolytes on the stability of the chlorophyll-protein complex seems to contradict the results of Stoll and Wiedemann (12). They claimed that when a suspension of the green material, treated with an electrolyte like NaC1, was shaken with ether, the pigment readily passed into the ether layer, and concluded that this was due to the presence of the salt.…”

“…Shafer (13), however, noticed that his suspensions, although never clear, were difficult to centrifuge. In a more extensive investigation of this point, Stoll and Wiedemann (12), as well as Anson (15), pointed out that their preparations were optically empty in bright field, when oil-immersion was used, but, in dark field, Stoll and Wiedemarm noticed Brownian motion of particles, which, they suggest, had been formed by agglomeration. We, too, have found that the purified pigment-protein, prepared as described above, contains particles or agglomerates sufficiently large for electrophoretic examination.…”

THE QUANTITATIVE ANALYSIS OF CHLOROPHYLLS a AND b IN PLANT EXTRACTS

“…As a consequence of this resistance the enzyme is generally not destroyed during extraction. Hydrolysis of the phytol group, which is accomplished both by chlorophyllase action and by alkaline treatment, renders the less hydrophobic chlorophyllides a and b, which accumulate in the polar phase on partitioning between ethyl ether and 22 per cent hydrochloric acid(l3, 17) or between petroleum ether and 80 per cent aqueous acetone. (l2)…”

Enzymology of the Plastids

“…First, in the chloroplasts thc proteins are cmihincd with ohlorophyll (4,13,43,-45, 65,66,86,144,145,150,164) ; licnce it is iiutursl to assume that they participate, either directly or indirectly, in the reactions of photosynthesis. Secondly, many enzymes are concentrated in the plastids, and this is the cause of manifold functions of these units.…”