Changes with aging in the levels of amino acids in rat CNS structural elements I. Glutamate and related amino acids

1989 ◽  
Vol 14 (6) ◽  
pp. 555-562 ◽  
Author(s):  
M. Banay-Schwartz ◽  
A. Lajtha ◽  
M. Palkovits
Keyword(s):  
Amino Acids ◽  
Structural Elements ◽  
Rat Cns

A Pyoverdin from the Antarctica Strain 51W of Pseudomonas fluorescens

1999 ◽  
Vol 54 (3-4) ◽  
pp. 156-162 ◽  
Author(s):  
Jessica Voss ◽  
Kambiz Taraz ◽  
Herbert Budzikiewicz
Keyword(s):  
Amino Acids ◽  
Pseudomonas Fluorescens ◽  
Binding Sites ◽  
Chemical Shifts ◽  
Chemical Degradation ◽  
Spectroscopic Methods ◽  
Extreme Conditions ◽  
Structural Elements ◽  
Nmr Data ◽  
Schirmacher Oasis

From the strain 51W of Pseudomonas fluorescens living under extreme conditions at the Schirmacher Oasis (Antarctica) a pyoverdin was obtained. Its structure was elucidated by chemical degradation and spectroscopic methods. The NMR data of the pyoverdin and of its Ga(III) complex were compared. Appreciable influences of the metal on the chemical shifts of the atoms at its binding sites were observed. Thus the structural elements involved in the complexation can be identified and coinciding signals of amino acids occurring more than once in the peptide chain can be separated.

THE PHYSICAL PROPERTIES OF SPIDER'S SILK AND THEIR ROLE IN THE DESIGN OF ORB-WEBS

1976 ◽  
Vol 65 (2) ◽  
pp. 483-506 ◽  
Author(s):  
MARK DENNY
Keyword(s):  
Amino Acids ◽  
Physical Properties ◽  
Breaking Stress ◽  
Structural Elements ◽  
Extension Ratio ◽  
Shock Absorbers ◽  
Orb Web ◽  
Degree Of Crystallization ◽  
Minimum Expenditure

1. Determinations were made of several physical properties of the viscid and frame silks of the orb-webs built by the spider Araneus sericatus (Cl.). 2. Both types of silk show a breaking stress of approximately 1 GN/m2 and an initial resilience of approximately 0.35. 3. The breaking extension ratio of viscid silk (λ = 3.00) is much greater than that of frame silk (λ = 1.25), and the viscid silk relaxes to a relatively greater extent. 4. These properties are correlated with the degree of crystallization of the protein from which the silk is made, this factor being controlled by the sequence of amino acids in the protein. 5. The physical properties of the viscid and frame silks allow them to function effectively as shock absorbers and structural elements, respectively; and allow the orb-web to function as an aerial filter with a minimum expenditure of material and energy.

Evolutionary relationships among the serpins

1993 ◽  
Vol 342 (1300) ◽  
pp. 101-119 ◽  
Keyword(s):  
Amino Acids ◽  
Proteinase Inhibitors ◽  
Gene Tree ◽  
Three Dimensional ◽  
Serine Proteinase ◽  
Amino Acid Sequences ◽  
Evolutionary Relationships ◽  
Evolutionary Divergence ◽  
Structural Elements ◽  
Sequence Alignments

The serpins are a widely distributed group of serine proteinase inhibitors found in plants, birds, mammals and viruses. Despite the great evolutionary divergence of these organisms, their serpins art highly conserved, both in sequence and structurally. Amino acid sequences were aligned by a combination of automatic algorithms and by consideration of conserved structural elements in those serpins for which crystal structures exist. The program HOMED was used which allowed the alignment of amino acids to be simultaneously converted into the equivalently aligned nucleotide sequences. The aligned amino acids were used as the basis for superposition of the four known three-dimensional structures for which coordinates are available and compared with an optimal three-dimensional superposition in order to estimate the reliability of the sequence alignment. Phylogenetic relationships implied by these nucleotide sequence alignments were determined by the method of maximum parsimony. The proposed gene tree suggested that as much diversity existed between the plant serpin and mammalian serpins as was present among mammalian serpins and provided further evidence that the architecture of serpin molecules is highly constrained.

scholarly journals Conserved structural elements specialize ATAD1 as a membrane protein extraction machine

2021 ◽  
Author(s):  
Lan Wang ◽  
Hannah Toutkoushian ◽  
Vladislav Belyy ◽  
Claire Kokontis ◽  
Peter Walter
Keyword(s):  
Amino Acids ◽  
Membrane Proteins ◽  
Protein Import ◽  
Protein Extraction ◽  
Structural Features ◽  
Live Cells ◽  
Mitochondrial Outer Membrane ◽  
Structural Elements ◽  
Peptide Substrate ◽  
Hydrophobic Membrane

AbstractThe mitochondrial AAA protein ATAD1 (in humans; Msp1 in yeast) removes mislocalized membrane proteins, as well as stuck import substrates from the mitochondrial outer membrane, facilitating their re-insertion into their cognate organelles and maintaining mitochondria’s protein import capacity. In doing so, it helps to maintain proteostasis in mitochondria. How ATAD1 tackles the energetic challenge to extract hydrophobic membrane proteins from the lipid bilayer and what structural features adapt ATAD1 for its particular function has remained a mystery. Previously, we determined the structure of Msp1 in complex with a peptide substrate (Wang et al., 2020). The structure showed that Msp1’s mechanism follows the general principle established for AAA proteins while adopting several structural features that specialize it for its function. We used the yeast growth assay to test the function of key amino acids within these structural elements. In this work, we determined the cryo-EM structures of the human ATAD1 in complex with a peptide substrate at near atomic resolution. The structures show that phylogenetically conserved structural elements adapt ATAD1 for its function while generally adopting a conserved mechanism shared by many AAA proteins. ATAD1’s distinguishing features include an abundance of aromatic amino acids that line the central pore proposed to give ATAD1 a firm grip on its substrate and a short α-helix at the C-terminus that strongly facilitates ATAD1’s oligomerization. We also developed a microscopy-based assay reporting on protein mislocalization, with which we directly assessed ATAD1’s activity in live cells.

scholarly journals Harnessing the functional diversity of plant cystatins to design inhibitor variants highly active against herbivorous arthropod digestive proteases

2021 ◽  
Author(s):  
Jonathan Tremblay ◽  
Marie-Claire Goulet ◽  
Juan Vorster ◽  
Charles Goulet ◽  
Dominique Michaud
Keyword(s):  
Amino Acids ◽  
Phage Display ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Structural Elements ◽  
New Approach ◽  
Digestive Proteases ◽  
Highly Active ◽  
Plant Cystatin ◽  
Selection Of

Protein engineering approaches have been proposed to improve the inhibitory properties of plant cystatins against herbivorous arthropod digestive proteases. These approaches typically involve the site-directed mutagenesis of functionally relevant amino acids, the production and selection of improved inhibitory variants by molecular phage display procedures, or the design of bi/multifunctional translational fusions integrating one or several cystatin inhibitory domains. Here, we propose a new approach where the function-related structural elements of a cystatin are substituted by the corresponding elements of an alternative cystatin. Cys protease inhibitory assays were first performed with 20 representative plant cystatins and model Cys proteases, including herbivorous arthropod digestive proteases, to appreciate the extent of functional variability among plant cystatin protein family members. The most, and less, potent of these cystatins were then used as donors of structural elements to create hybrids of tomato cystatin SlCYS8 used as a model recipient inhibitor. Our data confirm the wide variety of cystatin protease inhibitory profiles among plant taxa. They also demonstrate the usefulness of these proteins as a pool of discrete structural elements for the design of cystatin variants with improved potency against herbivorous pest digestive Cys proteases.

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