The present disclosure provides methods and compositions for directed to synthetic block copolymer proteins, expression constructs for their secretion, recombinant microorganisms for their production, and synthetic fibers (including advantageously, microfibers) comprising these proteins that recapitulate many properties of natural silk. The recombinant microorganisms can be used for the commercial production of silk-like fibers.

The disclosure relates to systems and methods for improving the manufacturing of silk solutions and powders containing silk fibroin obtained from silkworm cocoons. The solutions and powders can be used to improve the post-harvest preservation of perishables and to improve the performance of packaging, including biodegradable packaging.

A composition is disclosed that includes pure silk fibroin-based protein fragments that are substantially devoid of sericin, wherein the composition has an average weight average molecular weight ranging from about 17 kDa to about 38 kDa, wherein the composition has a polydispersity of between about 1.5 and about 3.0, wherein the composition is substantially homogeneous, wherein the composition between 0 ppm to about 500 ppm of inorganic residuals, and wherein the composition includes between 0 ppm to about 500 ppm of organic residuals.

An object of the present invention is to provide a method for advantageously producing a protein molded article which can solve a problem caused by esterification of a hydroxyl group contained in a protein while maintaining a sufficient strength. A method for producing a protein molded article according to the present invention includes a step of bringing a raw material molded article containing a protein in which a hydroxyl group is esterified into contact with an acidic or basic medium in a state of applying a tensile force, thus hydrolyzing an ester group.

A silk fibroin nerve graft fused with NT3 and a preparation method therefor is provided. The method includes the steps of: synthesizing a gene fragment containing a silk fibroin light chain and NT-3, connecting the fragment to a pET-30 expression vector, and transferring the obtained recombinant expression vector into BL21 Escherichia coli to obtain a fusion protein; placing a silk fibroin fiber web in a mold, mixing the fusion protein and a silk fibroin solution, and performing freeze drying to enable the silk fibroin to be crosslinked with the fusion protein to form a nerve conduit; and after deformation processing, finally obtaining a silk fibroin nerve graft having NT-3 activity. The silk fibroin nerve graft can provide a mechanical support, exert nerve protection and nerve regeneration promotion functions in a long term, and adjust the proportion of NT-3 bioactive peptides in the nerve conduit, facilitating repair of nerve injuries.

The present invention, in some aspects, provides compositions including a solution comprising a plurality of exfoliated silk microfibrils and/or exfoliated silk nanofibrils, wherein the micro- or nano-fibrils are characterized as having a substantially nematic structure, as well as methods for making and using the same.

Provided is a gene expression system, suitable for expression in an insect, comprising an insect muscle actin promoter operably linked to a marker gene, which overcomes or ameliorates one or more of: cost of rearing; amount of handling; errors in identification due to human error or loss of marker by the insect; and health concerns related to the effects of marker powders on workers in mass rearing facilities.

The present disclosure provides methods and compositions for directed to synthetic block copolymer proteins, expression constructs for their secretion, recombinant microorganisms for their production, and synthetic fibers (including advantageously, microfibers) comprising these proteins that recapitulate many properties of natural silk. The recombinant microorganisms can be used for the commercial production of silk-like fibers.

The object of the present invention is a method for the production of block polymers comprising a firstand a second block comprising the method steps: A) providing a first block having a nucleophilic peptide sequence for afirst transpeptidase enzyme, B) providing a second block having a peptide recognition sequence for the first transpeptidase enzyme, C) linking the first block to the second block by means of the first transpeptidase enzyme, wherein the first and second blocks are independently selected from nanoparticles, non-peptide polymers, and recombinant proteins. Such a production method makes it possible to build block polymers from identical or different blocks in a particularly simple and controlled manner.

Disclosed are methods, compositions, and systems for transforming silkworms to produce spider silk and analogs of spider silk. In certain embodiments, the method may include inserting a DNA sequence coding for at least a portion of a spider silk fibroin polypeptide, or an analog of a spider silk fibroin polypeptide, positioned between at least a portion of the 5′ and 3′ ends of a silkworm fibroin gene to generate a fusion gene construct having a sequence that encodes for a polypeptide comprising both spider silk fibroin and silkworm silk fibroin sequences. In certain embodiments, the fused gene is able to replace a native gene present in the silkworm such that the transformed silkworm expresses a polypeptide comprising a spider silk fibroin polypeptide, or an analog thereof, and expresses significantly less of the native silkworm silk.