High-strength and ultra-tough supramolecular polyamide spider silk fibers assembled via specific covalent and reversible hydrogen bonds.

Achieving ultra-high tensile strength and exceptional toughness is a longstanding goal for structural materials. However, previous attempts using covalent and non-covalent bonds have failed, leading to the belief that these two properties are mutually exclusive. Consequently, commercial fibers have been forced to compromise between tensile strength and toughness, as seen in the differences between nylon and Kevlar.

Disabling spidroin N-terminal homologs' reverse reaction unveils why its intermolecular disulfide bonds have not evolved for 380 million years.

Spiders, ubiquitous predators known for their powerful silks, rely on spidroins that self-assemble from high-concentration solutions stored in silk glands, which are mediated by the NT and CT domains. CT homodimers containing intermolecular disulfide bonds enhance silk performance, promoting spider survival and reproduction. However, no NT capable of forming such disulfide bonds has been identified.

Comparative Proteome Analysis of Serum Uncovers Differential Expression of Proteins in Donkeys (Equus Asinus) With Endometritis Caused by Escherichia Coli.

Endometritis is a common disease in donkeys that causes economic losses to donkey farms and the common cause is bacterial infection. Uterine flush fluid proteomics has been used to study protein biomarkers associated with endometritis in mares. As a convenient diagnostic tool, serum proteomics has not been studied yet in equine species with endometritis.

Endometrial and vaginal microbiome in donkeys with and without clinical endometritis.

Endometrial and vaginal microbiomes are critical in the study of endometritis, which is an important cause of infertility in donkeys. Our objective was to investigate the difference of the endometrial and vaginal microbiomes between healthy donkey jennies (group C) and jennies with endometritis (group E). Endometrial and vaginal swab samples were collected, and the 16 s rRNA gene amplicon high-throughput sequencing technique was applied to identify the microbial composition in the samples.

Antimicrobial Susceptibility of Bacterial Isolates from Donkey Uterine Infections, 2018-2021.

Background: Endometritis is a common reproductive disease in equine animals. No investigation about the bacterial characteristics and antimicrobial susceptibility pattern of donkeys with endometritis has thus far been reported.

Objectives: To determine the common uterine bacterial isolates from donkeys with endometritis and to evaluate their susceptibility to antimicrobials used for the treatment thereof.

Wet-Spinning Synthetic Fibers from Aggregate Glue: Aggregate Spidroin 1 (AgSp1).

Spidroin has the potential of wide applications in the biomedicine field as a natural biomaterial. Various synthetic fibers with outstanding mechanical properties have been produced from different spidroins. However, studies on the structural analysis or biomimetic exploration of aggregate spidroin (AgSp) remain scarce.

Tough synthetic spider-silk fibers obtained by titanium dioxide incorporation and formaldehyde cross-linking in a simple wet-spinning process.

Due to its unique mechanical properties, spider silk shows great promise as a strong super-thin fiber in many fields. Although progress has been made in the field of synthesizing spider-silk fiber from recombinant spidroin (spider silk protein) in the last few decades, methods to obtain synthetic spider-silk fibers as tough as natural silk from small-sized recombinant protein with a simple spinning process have eluded scientists. In this paper, a recombinant spidroin (MW: 93.

Tensile properties of synthetic pyriform spider silk fibers depend on the number of repetitive units as well as the presence of N- and C-terminal domains.

Spiders can spin seven different types of silk, some of which are well characterized, but studies on natural and synthetic pyriform silks are few. In this study, recombinant spidroins composed of one to three pyriform repeat units from Araneus ventricosus, in some cases flanked with non-repetitive N- and C-terminal domains (NT and CT), were produced and spun into continuous silk fibers using a wet-spinning process in organic solvents. All the fibers showed high and similar tensile strain (60-80%), but the Young's modulus, stress and toughness of fibers increased with increasing number of repeat units and in the presence of NT and CT as well.

Molecular cloning and analysis of the full-length aciniform spidroin gene from Araneus ventricosus.

Orb-web spiders produce more than seven different protein-based silks/glues by specialized abdominal glands for different uses. Prey-wrapping silk is secreted by aciniform glands for wrapping prey and forming the inner layer of egg case, and is almost twice as tough as other silks because of high strength and extensibility. So far, only two complete gene sequences have been obtained for aciniform spidroins (AcSp1).