Aspartimide (Asi) formation is one of the most serious side reactions that can occur both during solid phase synthesis and storage of peptides containing aspartic acid. Although numerous studies on the mechanism of Asi formation conducted so far, the problem still remains unresolved and relatively little is known about the impact of this side reaction on biological properties of such modified peptides. In the present work we characterized the effect of Asi formation on biological properties of galanin(1-15) analogue modified in position 14 with aspartic acid, investigating its action on rat isolated gastric smooth muscles and glucose-induced insulin secretion from rat isolated islets of Langerhans. Our results show that this side process may adversely affect biological properties of such modified peptides. As we expected, modification of GAL(1-15)NH(2) structure changed the interaction of GAL(1-15)NH(2) with its receptors and consequently yielded peptide which, in studies on insulin secretion, showed insulinotropic- and antagonistic activities as compared to Asi-free analogue.
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http://dx.doi.org/10.2174/092986610792231447 | DOI Listing |
Function (Oxf)
January 2025
Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan.
The ATP-sensitive potassium (KATP) channels, composed of Kir6.2 and SUR1 subunits, are essential for glucose homeostasis. While the role of pancreatic KATP channels in regulating insulin secretion is well-documented, the specific contributions of neuronal KATP channels remain unclear due to challenges in precisely targeting neuronal subpopulations.
View Article and Find Full Text PDFDiabetes
January 2025
Department of Biology & Institute of Biochemistry, Carleton University, Ottawa, ON, Canada.
Cancer survivors have an increased risk of developing Type 2 diabetes compared to the general population. Patients treated with cisplatin, a common chemotherapeutic agent, are more likely to develop metabolic syndrome and Type 2 diabetes than age- and sex-matched controls. Surprisingly, the impact of cisplatin on pancreatic islets has not been reported.
View Article and Find Full Text PDFJ Endocrinol
January 2025
N Inagaki, Department of Diabetes, Endocrinology and Nutrition, Kyoto University, Kyoto, Japan.
Glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1 RAs) are widely used as antidiabetic and anti-obesity agents. Although conventional GLP-1 RAs such as liraglutide and semaglutide are acylated with fatty acids to delay their degradation by dipeptidylpeptidase-4 (DPP-4), the manufacturing process is challenging. We previously developed selectively lipidated GLP-1 peptides at their only tryptophan residue (peptide A having one 8-amino-3,6-dioxaoctanoic acid (miniPEG) linker and peptide B having three miniPEG linkers).
View Article and Find Full Text PDFDiabetes Metab Syndr Obes
January 2025
Department of Diabetes, Metabolism and Endocrinology, Toho University Graduate School of Medicine, Tokyo, Japan.
Purpose: Imeglimin is a novel oral antidiabetic agent that improves glucose tolerance. This study aimed to investigate the efficacy of combining imeglimin with dipeptidyl peptidase-4 inhibitor (DPP-4i), the most frequently prescribed first-line treatment for patients with type 2 diabetes (T2D) in Japan, to improve glycemic control.
Patients And Methods: Eleven patients with T2D treated with DPP-4i alone (6.
Diabetes Obes Metab
January 2025
Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Aims: To compare the probability of achieving diabetes remission in individuals with different phenotypes of insulin sensitivity, insulin secretion, and beta cell function and further detect the effects of diet, exercise, and lifestyle education intervention on these indexes.
Methods: Three-hundred and one participants who had glycated haemoglobin (HbA1c) data at baseline and after intervention were included for this post hoc analysis. We used the multi-way analysis of variance to assess the differences between the diabetes remission and non-remission groups or between intervention groups in changes of the indexes of insulin sensitivity, insulin secretion, and beta cell function.
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