| 主权项 |
1. A method for simultaneously recovering both ribulose-1,5-bisphosphate (RUBP) carboxylase/oxygenase (“rubisco”) and non-rubisco soluble leaf proteins from plant leaves, which method is conducted throughout at a temperature between about 0°-about 25° Celsius, comprising the steps of:
(a) simultaneously disrupting the cell walls of plant leaves and contacting rubisco and non-rubisco soluble proteins released from the disrupted plant leaves with a buffer solution, so that disrupted leaf materials and rubisco and non-rubisco soluble leaf proteins are exposed to the buffer solution and both the rubisco and non-rubisco soluble leaf proteins solubilize and are kept in the buffer solution, wherein the buffer solution (i) has a solute concentration between 0.025 M and 0.3 M; (ii) is present in a buffer-to-leaf ratio of greater than approximately 1:2 but not more than approximately 8:1; (iii) has a pH between 6.5 and 9.0; (iv) has a buffering region that is effective within the pH value of (iii); and (v) optionally comprises a chelating agent and/or a reducing agent; (b) removing from the buffer solution produced in step (a) substantially all cellulosic material to produce a buffer solution containing plant chloroplast material and the rubisco and non-rubisco soluble leaf proteins, which proteins remain solubilized therein, which step (b) occurs without adsorption on a solid support or removal by filtration of the rubisco or non-rubisco soluble leaf proteins; (c) removing from the buffer solution produced in step (b) at least 80% of the plant chloroplast material to produce a buffer solution containing the rubisco and non-rubisco soluble leaf proteins, which proteins remain solubilized therein, which step (c) occurs without adsorption on a solid support or removal by filtration of the rubisco or non-rubisco soluble leaf proteins; wherein throughout steps (a), (b) and (c) both the rubisco and non-rubisco soluble leaf proteins remain solubilized and kept in the buffer solution while cellulosic material and plant chloroplast material are sequentially removed therefrom, and (d) drying down together in one product both the solubilized rubisco and non-rubisco soluble leaf proteins from the buffer solution, wherein said method further comprises steps between step (c) and step (d): (aa) precipitating without denaturing soluble leaf proteins by conducting an isoelectric point precipitation on the buffer solution containing the solubilized leaf proteins, for up to 40 minutes at a pH of 5.3 equivalent to the isoelectric point of the soluble leaf proteins, or within .5 pH units of pH 5.3 of the isoelectric point; (bb) removing any supernatant; and (cc) resuspending the precipitated soluble leaf proteins in the buffer solution. |
