In some type-3 copper proteins (molluskan hemocyanin, catechol oxidase and fungal tyrosinase) one of the histidine residues, liganding the Cu(A) atom of the dinuclear copper active site, is covalently linked to a cysteine residue by a thioether bridge. The purpose of this study was to disclose the function of this bridge. Mass spectral analysis of a peptide, isolated from Rapana thomasiana (gastropodan mollusk) hemocyanin, indicated a stabilization of the peptide structure in the region of the bridge. Molecular modeling of three thioether containing type-3 copper proteins using the dead-end elimination method showed that the concerned histidine would be very flexible if not linked to the cysteine. Also, the side chain orientation of the histidine is rather exceptional, as evidenced by statistical data from the protein databank. It is suggested that the role of the bridge is to fix the histidine in an orientation that is optimal for coordination of the Cu(A) atom.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.peptides.2006.12.004 | DOI Listing |
Front Chem
January 2025
African Society for Bioinformatics and Computational Biology, Cape Town, South Africa.
Introduction: Treatment of type 2 diabetes (T2D) remains a significant challenge because of its multifactorial nature and complex metabolic pathways. There is growing interest in finding new therapeutic targets that could lead to safer and more effective treatment options. Takeda G protein-coupled receptor 5 (TGR5) is a promising antidiabetic target that plays a key role in metabolic regulation, especially in glucose homeostasis and energy expenditure.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Department of Biochemistry, Bahauddin Zakariya University, Multan, Pakistan.
Platelet-derived growth factor alpha (PDGFRA) plays a significant role in various malignant tumors. PDGFRA expression boosts thyroid cancer cell proliferation and metastasis. Radiorefractory thyroid cancer is poorly differentiated, very aggressive, and resistant to radioiodine therapy.
View Article and Find Full Text PDFdescribes the ability of biological macromolecules to transmit signals spatially through the molecule from an site – a site that is distinct from binding sites of primary, endogenous ligands – to the functional or active site. This review starts with a historical overview and a description of the classical example of allostery – hemoglobin – and other well-known examples (aspartate transcarbamoylase, Lac repressor, kinases, G-protein-coupled receptors, adenosine triphosphate synthase, and chaperonin). We then discuss fringe examples of allostery, including intrinsically disordered proteins and inter-enzyme allostery, and the influence of dynamics, entropy, and conformational ensembles and landscapes on allosteric mechanisms, to capture the essence of the field.
View Article and Find Full Text PDFBMC Ecol Evol
January 2025
School of GeoSciences, University of Edinburgh, Edinburgh, Scotland.
Pterosaurs were the first vertebrates to evolve active flight. The lack of many well-preserved pterosaur fossils limits our understanding of the functional anatomy and behavior of these flight pioneers, particularly from their early history (Triassic to Middle Jurassic). Here we describe in detail the osteology of an exceptionally preserved Middle Jurassic pterosaur, the holotype of Dearc sgiathanach from the Isle of Skye, Scotland.
View Article and Find Full Text PDFJ Neural Transm (Vienna)
January 2025
Institut für Zellbiochemie, OE 4310, Medizinische Hochschule Hannover, 30623, Hannover, Germany.
Botulinum neurotoxins (BoNT) are established biopharmaceuticals for neuromuscular and secretory conditions based on their ability to block neurotransmitter release from neurons by proteolyzing specific soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. Recently, a mutant catalytic domain of serotype E (LC/E) exhibiting 16 mutations was reported to cleave the phosphatase and tensin homolog (PTEN). This molecule represents an attractive new target in neurons as several reports support PTEN knockdown as a strategy to stimulate axonal regeneration after injury.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!