Metallothionein (MT) plays a significant role in heavy metal removal, antioxidant defense, and immune regulation. The current predominant approach for obtaining natural MT is extraction from tissue, which often entails complex procedures resulting in limited yields. In recent years, researchers have adopted the strategy of fusing labels such as GST or His for the heterologous expression of MT. However, a challenge in industrial production arises from the subsequent removal of these labels, which often leads to a significant reduction in the yield. The fusion with elastin-like polypeptides (ELPs) offers a promising solution for achieving soluble expression of the target protein, while providing a simple and fast purification process. In this study, ELP was fused with MT, which significantly up-regulated the soluble expression of MT. The fusion protein ELP-MT with the purity above 97% was obtained efficiently and simply by inverse transition cycling (ITC). ELP-MT exhibited a remarkable 2,2'-azinobis(3-ethylbenzothiazoline-6- sulfonic acid) ammonium salt (ABTS) scavenging activity, with the half maximal inhibitory concentration (IC₅₀) of 0.77 μmol/L, which was 53.7 times that of the vitamin E derivative Trolox. In addition, the fusion protein demonstrated strong 1,1-diphenyl-2-trinitrohydrazine (DPPH) scavenging ability. Furthermore, ELP-MT had no toxicity to the proliferation and promoted the adhesion and migration of NIH/3T3 cells. All these results indicated that ELP-MT had good biocompatibility. We constructed the fusion protein ELP-MT combining the unique properties of MT and elastin, laying a technical foundation for the large-scale production of recombinant MT and facilitating the applications in food, health supplement, and cosmetic industries.
Metallothionein/metabolism* ; Elastin/chemistry* ; Recombinant Fusion Proteins/pharmacology* ; Mice ; Animals ; Peptides/metabolism* ; Escherichia coli/metabolism* ; NIH 3T3 Cells

Many factors influence the elastin-like polypeptides (ELPs) self-assembled into micron-sized particles. However, few efforts were made to investigate these factors. Using the ELPs [KV8F]n as the target, we studied systematically the factors with the dynamic light scattering. Our results show that the particle size increased and the uniform of particles decreased with the increase of the molecular weight. The analysis of size variation in self-assembled ELPs in response to changes in salt concentration indicated that the size increased with increasing the salt concentration, and the opposite response was observed when the concentration was above 0.4 mol/L. Under these conditions, the particles are micron-sized and larger than 1.1 μm. However, when the fusions containing the same ELPs and xylanase or 1,3-propanediol oxidoreductase, the size of the self-assembled ELPs particles decreased dramatically, which was only about 1/10 of that of the free ELPs. We proposed that the solvent accessible charged area of the enzymes could interact with the ELPs, the sterical hindrance of the enzymes prevent the aggregation of the ELPs. This might be the most important parameter in altering the particle size sharply.
Elastin ; chemistry ; Molecular Weight ; Particle Size ; Peptides ; chemistry ; Salts ; chemistry

Elastin is a natural biomedical material of great potential. Being endowed with the special crosslinking and hydrophobic structure, elastin retains many good properties such as good elasticity, ductibility, biocompatibility, biodegradability and so on. Nowadays, elastin as a material, which is gradually attracting people' s attention in the biomedical materials field, has been used as tissue engineering scaffolds, derma substitutes and other biomedical materials. In this context, a systematic review on the characteristics of elastin as a biomedical material and on the actuality of its application is presented. Future developments of elastin in the field of biomedical applications are also discussed.
Biocompatible Materials ; Elastin ; chemistry ; physiology ; Humans ; Skin, Artificial ; Tissue Scaffolds

In order to provide morphological data and theoretical basis for pig-to-human hepatic xenotransplantation, the difference in morphological parameters and vessel wall structural factors between human and porcine hepatic portal vein was studied. From human subjects and pigs of varying ages, hepatic portal veins were collected, paraffin-embedded and cut into sections. The histological structures were stained with HE, and elastin, collagen and smooth muscles were stained with Weigert, Aniline blue and orange G, respectively. Morphological parameters and relative contents of structural components were determined under microscopy and by computer image analysis system, respectively. The results showed that histological structures of human and porcine hepatic portal vein wall were similar. Caliber, wall thickness, lumen and wall area in pigs increased with age, all in linear correlation to months. Morphological parameters of 6- month-old pigs were similar to those of human. In pigs, collagen content increased gradually with months, elastin content remained relatively stable, smooth muscle content reached the peak at the 3rd month, and collagen/elastin (C/E) rose gradually. The contents of collagen and elastin in porcine hepatic portal vein wall were lower, while the content of smooth muscle was higher than in human, and C/E at the 5th and 6th month was similar to that in human. It is concluded that morphological parameters and contents of structural components of porcine hepatic portal vein vary with age. At the 6 month, its caliber, wall thickness, lumen and wall area are similar to those of human. There are differences in contents of structural components between human and pigs. However, in terms of C/E, mechanic properties of pigs at the 5th and 6th month mimic those of human, hence inosculation is viable in xenotrans-plantation between pigs and human.
Collagen/*analysis ; Elastin/*analysis ; Image Processing, Computer-Assisted ; Liver Transplantation ; Muscle, Smooth, Vascular/cytology ; Portal Vein/*anatomy & histology ; Portal Vein/chemistry ; Swine ; Transplantation, Heterologous