A protein construct including a gene encoding a light-sensitive protein fused to at least one of either a low complexity sequence, an intrinsically disordered protein region (IDR), or a repeating sequence of a linker and another gene encoding a light-sensitive protein. Among the many different possibilities contemplated, the protein construct may also advantageously include cleavage tags. This protein construct may be utilized for a variety of functions, including a method for protein purification, which requires introducing the protein construct into a living cell, and inducing the formation of clusters by irradiating the construct with light. The method may also advantageously include cleaving a target protein from an IDR, and separating the clusters via centrifuge. A kit for practicing in vivo aggregation or liquid-liquid phase separation is also included, the kit including the protein construct and a light source capable of producing a wavelength that the light-sensitive protein will respond to.

A protein construct including a gene encoding a light-sensitive protein fused to at least one of either a low complexity sequence, an intrinsically disordered protein region (IDR), or a repeating sequence of a linker and another gene encoding a light-sensitive protein. Among the many different possibilities contemplated, the protein construct may also advantageously include cleavage tags. This protein construct may be utilized for a variety of functions, including a method for protein purification, which requires introducing the protein construct into a living cell, and inducing the formation of clusters by irradiating the construct with light. The method may also advantageously include cleaving a target protein from an IDR, and separating the clusters via centrifuge. A kit for practicing in vivo aggregation or liquid-liquid phase separation is also included, the kit including the protein construct and a light source capable of producing a wavelength that the light-sensitive protein will respond to.

The present invention relates in a first aspect to a method for the purification of biological macromolecular complexes. Typically, no chromatography steps are applied. That is, the present invention relates to a method for the purification of biological macromolecular complexes Furthermore, the present invention relates to a method for crystallization of biological macromolecular complexes comprising the step of purification as described followed by crystallization in a reservoir solution containing a water-soluble polymer. Furthermore, purified biological macromolecular complexes obtainable by the method according to the present invention are provided as well as crystallized biological macromolecular complexes. Finally, a method for determining the suitability of a candidate compound for inhibiting the 20S proteasome of an individual is provided. Said method is particularly useful in personalized medicine identifying suitable inhibitors of the 20S proteasome in individuals for treating, ameliorating or preventing a cancer, an autoimmune disease, a muscular dystrophy, emphysema or cachexia accompanying cancer or AIDS.

The present invention relates in a first aspect to a method for the purification of biological macromolecular complexes. Typically, no chromatography steps are applied. That is, the present invention relates to a method for the purification of biological macromolecular complexes Furthermore, the present invention relates to a method for crystallization of biological macromolecular complexes comprising the step of purification as described followed by crystallization in a reservoir solution containing a water-soluble polymer. Furthermore, purified biological macromolecular complexes obtainable by the method according to the present invention are provided as well as crystallized biological macromolecular complexes. Finally, a method for determining the suitability of a candidate compound for inhibiting the 20S proteasome of an individual is provided. Said method is particularly useful in personalized medicine identifying suitable inhibitors of the 20S proteasome in individuals for treating, ameliorating or preventing a cancer, an autoimmune disease, a muscular dystrophy, emphysema or cachexia accompanying cancer or AIDS.

The invention relates to a process for the selective concentration of immunoglobulins or other proteins that contain an Fc domain (target protein), comprising the following steps: a. preparing a solution that contains the target protein; b. incorporating an Fc-binding protein with precisely two binding sites under conditions that allow binding to occur; c. separating the precipitate from the liquid phase; d. undoing the binding of the target protein from the Fc-binding protein.

The invention relates to a process for the selective concentration of immunoglobulins or other proteins that contain an Fc domain (target protein), comprising the following steps: a. preparing a solution that contains the target protein; b. incorporating an Fc-binding protein with precisely two binding sites under conditions that allow binding to occur; c. separating the precipitate from the liquid phase; d. undoing the binding of the target protein from the Fc-binding protein.

The present invention relates to a mannitol-based amphipathic compound, a method of preparing the same, a method of extracting, solubilizing, stabilizing or crystallizing a membrane protein using the compound, and a method of analyzing a structure of the membrane protein under an electron microscope using the compound. When the mannitol-based compound according to the present invention is used, the membrane protein can be stably stored in an aqueous solution for a prolonged period of time and thus can be applied to analysis of functions and structures thereof. Since the analysis of the structures and functions of the membrane protein is one of the fields of most interest in biology and chemistry currently, and more than half of new drugs currently in development are targeting membrane proteins, the present invention is applicable to research on the structures of membrane proteins closely related to the development of the new drugs.

The present invention relates to a mannitol-based amphipathic compound, a method of preparing the same, a method of extracting, solubilizing, stabilizing or crystallizing a membrane protein using the compound, and a method of analyzing a structure of the membrane protein under an electron microscope using the compound. When the mannitol-based compound according to the present invention is used, the membrane protein can be stably stored in an aqueous solution for a prolonged period of time and thus can be applied to analysis of functions and structures thereof. Since the analysis of the structures and functions of the membrane protein is one of the fields of most interest in biology and chemistry currently, and more than half of new drugs currently in development are targeting membrane proteins, the present invention is applicable to research on the structures of membrane proteins closely related to the development of the new drugs.

A method of producing protein products including alpha-1-proteinase inhibitor, gamma globulin, albumin, and other proteins from plasma includes steps of: (1) adding a salt to the blood product to produce a first intermediate, wherein the salt comprises between 11-13 wt % of the first intermediate; (2) separating the first intermediate to produce a first supernatant and a first paste; (3) adding a salt to the first intermediate to produce a second intermediate, wherein the salt comprises between 21-23 wt % of the second intermediate; (4) separating the second intermediate to produce a second supernatant and a second paste; (5) separating a third intermediate from the second supernatant by affinity chromatography; and (6) separating the third intermediate by ion exchange chromatography to produce an eluate containing the protein product. Advantageously, the inventive methods are simple and produce alpha-1-proteinase inhibitor, gamma globulin, albumin, and other proteins in high yields.

A method of producing protein products including alpha-1-proteinase inhibitor, gamma globulin, albumin, and other proteins from plasma includes steps of: (1) adding a salt to the blood product to produce a first intermediate, wherein the salt comprises between 11-13 wt % of the first intermediate; (2) separating the first intermediate to produce a first supernatant and a first paste; (3) adding a salt to the first intermediate to produce a second intermediate, wherein the salt comprises between 21-23 wt % of the second intermediate; (4) separating the second intermediate to produce a second supernatant and a second paste; (5) separating a third intermediate from the second supernatant by affinity chromatography; and (6) separating the third intermediate by ion exchange chromatography to produce an eluate containing the protein product. Advantageously, the inventive methods are simple and produce alpha-1-proteinase inhibitor, gamma globulin, albumin, and other proteins in high yields.