A method of preparing a hydroxytyrosol sturgeon skin gelatin film with antioxidant activity and Salmonella detection ability includes: (1) mixing a neutral red indicator solution and distilled water at room temperature to obtain a mixture solution, and adding 1 mol/L NaHCO.sub.3 solution to the mixture solution until discoloration to obtain an alkaline solution; (2) adding an amount of the alkaline solution obtained in step (1) to a mixture of Sturgeon skin gelatin and distilled water to obtain an alkaline gelatin solution; (3) adding hydroxytyrosol and glycerin and propylene glycol to the alkaline gelatin solution to obtain a hydroxytyrosol gelatin solution, and heating the hydroxytyrosol gelatin solution at 40-70° C.; (4) ultrasonicating the hydroxytyrosol gelatin solution from step (3), placing the hydroxytyrol gelatin solution evenly on a clean plexiglass plate, drying the hydroxytyrol gelatin solution on an ultra-clean worktable to obtain the hydroxytyrosol sturgeon skin gelatin film.

The invention relates to a composition of peptides having an aminogram in which: glycine, hydroxyproline and proline are in molar quantities such that the ratio of each quantity to the sum of the molar quantities of the amino acids in the composition is comprised between 20.0% and 24.5%, between 6.0% and 12.0% and between 10.6% and 14.6%, respectively; the peptide composition comprising a quantity of peptides with a molecular weight lower than 1400 Da such that the ratio of said quantity to the quantity of peptides in the composition is less than 40%; the molecular weight and the quantity of peptides in the composition being determined by exclusion chromatography. The invention likewise relates to such a composition to be used as a drug. The invention further relates to such a composition to be used as a food supplement.

Described herein are protein compositions comprising low molecular weight proteins, water insoluble, and non-hygroscopic properties, methods of treating diseases or conditions using such compositions, and methods of inhibiting angiotensin-1-converting enzyme (ACE) using the same.

The present disclosure provides fish-derived peptides with ACE inhibitory activity, and methods of producing peptide isolates comprising the fish-derived peptides. The present disclosure also provides pharmaceutical products, dietary supplements, and functional foods including the peptide isolates, and method of lowering blood pressure of a subject by administering to the subject one or more of the fish-derived peptides.

Systems, compositions, and methods for target site-specific insertion of a transgene of interest to a subject genome are provided. Systems and methods that facilitate primed reverse transcription (TPRT) mediated by retroelement derived reverse transcriptase (RTs) site-specific transgene insertion are also provided.

Provided herein are a voltage indicator and a method of measuring voltage. The voltage indicator includes a membrane-localized voltage-sensitive protein coupled to a capture protein. The method of measuring voltage includes administering a voltage indicator including a membrane-localized voltage-sensitive protein coupled to a capture protein, and determining changes in fluorescence of a small-molecule fluorescent dye captured by the capture protein.

This disclosure relates to variable lymphocyte receptors (VLRs) modifications such as humanized sequences and polypeptides comprising such sequences that specifically bind a target molecule and uses related thereto. In certain embodiments, the disclosure relates to recombinant polypeptide VLRs disclosed herein and variants thereof. In certain embodiments, this disclosure relates to treating or preventing a disease or condition comprising administering an effective amount of a recombinant polypeptide or variant disclosed herein to a subject in need thereof.

Provided herein are a voltage indicator and a method of measuring voltage. The voltage indicator includes a membrane-localized voltage-sensitive protein coupled to a capture protein. The method of measuring voltage includes administering a voltage indicator including a membrane-localized voltage-sensitive protein coupled to a capture protein, and determining changes in fluorescence of a small-molecule fluorescent dye captured by the capture protein.

A method of preparing a ddx27-deletion zebrafish mutant, including: determining a target of ddx27 knockout on a sixth exon of the ddx27 in a zebrafish and designing a gRNA sequence; using primers T7-ddx27-sfd and tracr rev for PCR amplification with a pUC19-gRNA scaffold plasmid as a template; purifying and transcribing the PCR product obtained in vitro to produce gRNA; introducing the gRNA and a Cas9 protein into the zebrafish; and culturing the zebrafish to obtain a zebrafish ddx27 mutant of stable inheritance. In addition, the application also discloses a phenotype of the ddx27-deletion zebrafish mutant, which plays an important role in investigating the biological function.

A method of preparing an anti-oxidation polypeptide having an amino acid sequence of SEQ ID NO:1 includes enzymatic hydrolysis of black shark skins, which serve as the raw material, with alkali protease, separation, purification, freezing, and drying to obtain the anti-oxidation polypeptide. Enzymatic hydrolysis conditions include 7.0-9.0 pH value, 40-50° C. temperature, 4.0-6.0 h enzymatic hydrolysis time, 2.0-4.0% primer concentration, and 9.0-10.0 wt % of enzymes.