The present paper reports on studies concerned with furnishing evidence for peptide synthesis in the course of in vitro proteolysis. To this end, the oxidized chain B from insulin (INS) (S = 5% in demineralized water) was subjected to tryptic proteolysis (E/S = 1/50; pH 5; 37 degrees C; 24 h). HPLC-as well as amino acid-and sequence analytical studies have shown that the heptapeptide INS 23-29 (Gly-Phe-Phe-Tyr-Thr-Pro-Lys) liberated by way of hydrolysis is linked by tryptic synthesis via transpeptidation or condensation to form a dimer which accounts for 15% of the amount of monomer. The results of the model trials show clearly that during in vitro proteolysis chemical reactions beyond hydrolytic cleavage of peptide bonds take place. In principle, plastein-like reactions (transpeptidation, condensation) can occur during each in vitro proteolysis.
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http://dx.doi.org/10.1002/food.19970410206 | DOI Listing |
Nucleic Acids Res
January 2025
College of Life Sciences, Beijing Normal University, Beijing 100875, China.
Mammalian J-domain protein DNAJC9 interacts with histones H3-H4 and is important for cell proliferation. However, its exact function remains unclear. Here, we show that, in the fission yeast Schizosaccharomyces pombe, loss of Djc9, the ortholog of DNAJC9, renders the histone chaperone Asf1 no longer essential for growth.
View Article and Find Full Text PDFJ Neurochem
January 2025
Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Canada.
Highly abundant in neurons, the cellular prion protein (PrP) is an obligatory precursor to the disease-associated misfolded isoform denoted PrP that accumulates in the rare neurodegenerative disorders referred to either as transmissible spongiform encephalopathies (TSEs) or as prion diseases. The ability of PrP to serve as a substrate for this template-mediated conversion process depends on several criteria but importantly includes the presence or absence of certain endoproteolytic events performed at the cell surface or in acidic endolysosomal compartments. The major endoproteolytic events affecting PrP are referred to as α- and β-cleavages, and in this review we outline the sites within PrP at which the cleavages occur, the mechanisms potentially responsible and their relevance to pathology.
View Article and Find Full Text PDFMol Reprod Dev
January 2025
Liv Hospital, Centre for Regenerative Medicine and Stem Cell Manufacturing (LivMedCell), İstanbul, Turkey.
In vitro maturation (IVM) is a form of assisted reproductive technology (ART) applied to obtain mature oocytes in culture. Decline in IVM success rates by age has led consideration of novel approaches based on cellular dynamics. Our aim was to achieve proteostasis in old bovine oocytes from 13 to 16-year-old bovine with a lower potential for fertilization.
View Article and Find Full Text PDFReprod Med Biol
January 2025
Laboratory of Animal Breeding and Reproduction, Division of Animal Science, School of Agriculture Utsunomiya University Utsunomiya Tochigi Japan.
Background: In vitro fertilization (IVF) and embryo transfer (ET) are widely used in reproductive biology. Despite the transfer of high-quality blastocysts, the implantation rate of IVF-derived blastocysts remains low after ET.
Methods: This article provides a comprehensive review of current research on embryo implantation regulators and their application to improve the implantation potential of IVF-derived blastocysts.
Cancers (Basel)
January 2025
Princess Maxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands.
Background: Proteolysis targeting chimeras (PROTACs) are heterobifunctional small molecules that utilize the ubiquitin-proteasome system to selectively degrade target proteins. This innovative technology has shown remarkable efficacy and specificity in degrading oncogenic proteins and has progressed through various stages of preclinical and clinical development for hematologic malignancies, including adult acute myeloid leukemia (AML). However, the application of PROTACs in pediatric AML remains largely unexplored.
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