A subset of growth hormone-secreting human pituitary tumours carries somatic mutations that inhibit GTPase activity of a G protein alpha chain, alpha(s). The resulting activation of adenylyl cyclase bypasses the cells' normal requirement for trophic hormone. Amino acids substituted in the putative gsp oncogene identify a domain of G protein alpha-chains required for intrinsic ability to hydrolyse GTP. This domain may serve as a built-in counter-part of the separate GTPase-activating proteins required for GTP hydrolysis by small GTP-binding proteins such as p21ras.
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http://dx.doi.org/10.1038/340692a0 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.
Enthalpy is often the focal point when designing monomers for polymer circularity, but much less is explored on how entropy can be exploited to create polymers with synergistic circularity and properties. Here, we design a series of spiro-lactones (SLs) with closed-chain cycloalk(en)yl substituents at the α,α-position of δ-valerolactone (δVL), which, when combined with the parent δVL and -α,α-dialkyl-substituted δVL with open-chain alkyl groups, provide a desired platform for exploring the circular polymer design by focusing on the entropy change of polymerization. These SLs exhibit finely balanced (de)polymerizability that is regulated chiefly by entropy differentiation, allowing both the facile synthesis of polyester PSLs ( up to 1000 kg mol) in a living fashion and selective depolymerization of the PSLs to completely recover monomers under mild conditions (using a recyclable catalyst at 100 °C).
View Article and Find Full Text PDFAnn Clin Transl Neurol
January 2025
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
Defining the CSF cytokine/chemokine and injury biomarker signature of glial fibrillary acidic protein (GFAP) autoimmunity can inform immunopathogenesis. CSF GFAP-IgG-positive samples (N = 98) were tested for 17 cytokines/chemokines, neurofilament light chain (NfL), and GFAP (ELLA, Bio-Techne). Controls included non-inflammatory (N = 42), AQP4-IgG-positive (N = 83), CNS infections (N = 13), and neurosarcoidosis (N = 32).
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Institute of Chemistry, Food Chemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 2, 06120 Halle (Saale), Germany.
Some lactic acid bacteria such as or contain genes encoding 4,6-α-glucanotransferases. These enzymes convert starch and maltodextrins into isomalto/malto-polysaccharides (IMMPs). Many studies focused on the properties of recombinant glucanotransferases, but limited knowledge is available on fermentative synthesis.
View Article and Find Full Text PDFHepatol Int
January 2025
Department of Virology II, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo, 162-8640, Japan.
Background And Aims: Hepatitis B virus (HBV) is prevalent worldwide and is difficult to eradicate. Current treatment strategies for chronic hepatitis B ultimately seek to achieve functional cure (FC); however, the factors contributing to FC remain unclear. We aimed to investigate the gut microbiota profiles of patients with chronic hepatitis B who achieved FC.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Inorganic Chemistry, Shahid Beheshti University, 1983969411, Tehran, Iran.
In a systematic study, six pseudopolymorphic coordination polymers containing the ditopic 1,3-di(pyridin-4-yl)urea ligand (4bpu) constructed with d metal cations, possessing the formula {[M(4bpu)I]S} [(M = Zn, Cd and Hg), (S = MeOH or EtOH)], namely Zn-MeOH, Zn-EtOH, Cd-MeOH, Cd-EtOH, Hg- and Hg-EtOH were obtained. The title compounds were characterized by single-crystal X-ray diffraction analysis (SC-XRD), elemental analysis (CHN), FT-IR spectroscopy, thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). The diffraction studies show that these compounds are isostructural 1D zig-zag chain coordination polymers which is also confirmed using XPac 2.
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