scholarly journals Are Granulins Copper Sequestering Proteins?

2020 ◽  
Author(s):  
Anukool A. Bhopatkar ◽  
Vijayaraghavan Rangachari
Keyword(s):  
Metal Binding ◽  
Divalent Cations ◽  
Structure And Function ◽  
Proteolytic Processing ◽  
Reduced Form ◽  
Binding Potential ◽  
Stress Regulation ◽  
Ph Conditions ◽  
And Function ◽  
First Time

AbstractGranulins (GRN 1-7) are short (∼6 kDa), cysteine-rich proteins that are generated upon the proteolytic processing of progranulin (PGRN). These modules, along with their precursor, have been implicated in multiple pathophysiological roles, especially in neurodegenerative diseases. Our previous investigations into GRN-3 and GRN-5 reveal them to be fully disordered in the reduced form and implicate redox sensitive attributes to the proteins. Such redox-dependent modulation has become associated with proteins involved in oxidative stress regulation and maintaining metal-homeostasis within cells. To probe whether GRNs play a contributory role in such functions, we tested the metal binding potential of the reduced form of GRNs -3 and -5 under neutral and acidic pH mimicking cytosolic and lysosomal conditions, respectively. We found, at neutral pH, both GRNs selectively bind Cu(II) and no other divalent cations. Binding of Cu(II) also partly triggered the oxidative multimerization of GRNs via uncoordinated cystines at both pH conditions. Furthermore, binding did not induce gain in secondary structure and the protein remained disordered. Overall, the results indicate that GRN-3 and -5 have a surprisingly strong affinity for Cu(II) in the pM range, comparable to known copper sequestering proteins. This data also hints at a potential of GRNs to reduce Cu(II) to Cu(I), a process that has significance in mitigating Cu-induced ROS cytotoxicity in cells. Together, this report uncovers a metal-coordinating capability of GRNs for the first time, which could have profound significance in their structure and function.

Strategies for Oral Delivery of Metal-Saturated Lactoferrin

2019 ◽  
Vol 20 (11) ◽  
pp. 1046-1051 ◽  
Author(s):  
Przemysław Gajda-Morszewski ◽  
Klaudyna Śpiewak-Wojtyła ◽  
Maria Oszajca ◽  
Małgorzata Brindell
Keyword(s):  
Biological Activity ◽  
Oral Delivery ◽  
Therapeutic Potential ◽  
Structure And Function ◽  
The Difference ◽  
And Function ◽  
First Time

Lactoferrin was isolated and purified for the first time over 50-years ago. Since then, extensive studies on the structure and function of this protein have been performed and the research is still being continued. In this mini-review we focus on presenting recent scientific efforts towards the elucidation of the role and therapeutic potential of lactoferrin saturated with iron(III) or manganese(III) ions. The difference in biological activity of metal-saturated lactoferrin vs. the unmetalated one is emphasized. The strategies for oral delivery of lactoferrin, are also reviewed, with particular attention to the metalated protein.

scholarly journals Influence of High Pressure on the Dimerization of ToxR, a Protein Involved in Bacterial Signal Transduction

2008 ◽  
Vol 74 (24) ◽  
pp. 7821-7823 ◽  
Author(s):  
Kai Linke ◽  
Nagarajan Periasamy ◽  
Matthias Ehrmann ◽  
Roland Winter ◽  
Rudi F. Vogel
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
High Pressure ◽  
Structure And Function ◽  
Transmembrane Segments ◽  
Bacterial Signal Transduction ◽  
Reporter Strains ◽  
And Function ◽  
First Time

ABSTRACT High hydrostatic pressure (HHP) is suggested to influence the structure and function of membranes and/or integrated proteins. We demonstrate for the first time HHP-induced dimer dissociation of membrane proteins in vivo with Vibrio cholerae ToxR variants in Escherichia coli reporter strains carrying ctx::lacZ fusions. Dimerization ceased at 20 to 50 MPa depending on the nature of the transmembrane segments rather than on changes in the ToxR lipid bilayer environment.

Oxidative protein folding in the mammalian endoplasmic reticulum

2004 ◽  
Vol 32 (5) ◽  
pp. 655-658 ◽  
Author(s):  
C.E. Jessop ◽  
S. Chakravarthi ◽  
R.H. Watkins ◽  
N.J. Bulleid
Keyword(s):  
Endoplasmic Reticulum ◽  
Mammalian Cells ◽  
Redox State ◽  
Structure And Function ◽  
Reduced Form ◽  
Secretory Proteins ◽  
Oxidative Protein Folding ◽  
Disulphide Bonds ◽  
And Function ◽  
Substrate Proteins

Native disulphide bonds are essential for the structure and function of many membrane and secretory proteins. Disulphide bonds are formed, reduced and isomerized in the endoplasmic reticulum of mammalian cells by a family of oxidoreductases, which includes protein disulphide isomerase (PDI), ERp57, ERp72, P5 and PDIR. This review will discuss how these enzymes are maintained in either an oxidized redox state that allows them to form disulphide bonds in substrate proteins or a reduced form that allows them to perform isomerization and reduction reactions, how these opposing pathways may co-exist within the same compartment and why so many oxidoreductases exist when PDI alone can perform all three of these functions.

Structural and functional studies of SAV1707 from Staphylococcus aureus elucidate its distinct metal-dependent activity and a crucial residue for catalysis

2021 ◽  
Vol 77 (5) ◽  
pp. 587-598
Author(s):  
Dong-Gyun Kim ◽  
Kyu-Yeon Lee ◽  
Sang Jae Lee ◽  
Seung-Ho Cheon ◽  
Yuri Choi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Metal Binding ◽  
Binding Mode ◽  
Structure And Function ◽  
Functional Study ◽  
Functional Studies ◽  
Dependent Endonuclease ◽  
Metal Selectivity ◽  
Metal Binding Domain ◽  
And Function

The metallo-β-lactamase fold is the most abundant metal-binding domain found in two major kingdoms: bacteria and archaea. Despite the rapid growth in genomic information, most of these enzymes, which may play critical roles in cellular metabolism, remain uncharacterized in terms of structure and function. In this study, X-ray crystal structures of SAV1707, a hypothetical metalloenzyme from Staphylococcus aureus, and its complex with cAMP are reported at high resolutions of 2.05 and 1.55 Å, respectively, with a detailed atomic description. Through a functional study, it was verified that SAV1707 has Ni2+-dependent phosphodiesterase activity and Mn2+-dependent endonuclease activity, revealing a different metal selectivity depending on the reaction. In addition, the crystal structure of cAMP-bound SAV1707 shows a unique snapshot of cAMP that reveals the binding mode of the intermediate, and a key residue Phe511 that forms π–π interactions with cAMP was verified as contributing to substrate recognition by functional studies of its mutant. Overall, these findings characterized the relationship between the structure and function of SAV1707 and may provide further understanding of metalloenzymes possessing the metallo-β-lactamase fold.

scholarly journals Crab scars reveal survival advantage of left-handed snails

2006 ◽  
Vol 2 (3) ◽  
pp. 439-442 ◽  
Author(s):  
Gregory P Dietl ◽  
Jonathan R Hendricks
Keyword(s):  
Social Interactions ◽  
Structure And Function ◽  
Snail Species ◽  
Left Handedness ◽  
Left Handed ◽  
Selection Processes ◽  
Living Organisms ◽  
And Function ◽  
First Time ◽  
Crab Predation

Biological asymmetries are important elements of the structure and function of many living organisms. Using the Plio–Pleistocene fossil record of crab predation on morphologically similar pairs of right- and left-handed snail species, we show here for the first time, contrary to traditional wisdom, that rare left-handed coiling promotes survival from attacks by right-handed crabs. This frequency-dependent result influences the balance of selection processes that maintain left-handedness at the species level and parallels some social interactions in human cultures, such as sports that involve dual contests between opponents of opposite handedness.

scholarly journals Structural Organization of Procaryotic and Eucaryotic Hsp90. INFLUENCE OF DIVALENT CATIONS ON STRUCTURE AND FUNCTION

1995 ◽  
Vol 270 (24) ◽  
pp. 14412-14419 ◽  
Author(s):  
Ursula Jakob ◽  
Ines Meyer ◽  
Hans Bügl ◽  
Stefanie André ◽  
James C. A. Bardwell ◽  
...  
Keyword(s):  
Structural Organization ◽  
Divalent Cations ◽  
Structure And Function ◽  
And Function

scholarly journals Foliar colleters in Macrocarpaea obtusifolia (Gentianaceae): anatomy, ontogeny, and secretion

Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Valdnéa Casagrande Dalvi ◽  
Lucas Siqueira Cardinelli ◽  
Renata Maria Strozi Alves Meira ◽  
Aristéa Alves Azevedo
Keyword(s):  
Chemical Nature ◽  
Developmental Stages ◽  
Structure And Function ◽  
Histochemical Analysis ◽  
Secretory Structures ◽  
Standard Type ◽  
Vegetative Organs ◽  
New Information ◽  
And Function ◽  
First Time

Colleters are secretory structures located in reproductive and (or) vegetative organs of many eudicots. In Gentianaceae Juss., the presence of foliar colleters has been neglected, and anatomical and histochemical studies are scarce. The objectives of this study were to investigate the anatomy, ontogeny, and chemical nature of the secretion found in Macrocarpaea obtusifolia (Griseb.) Gilg colleters to establish a relationship between their structure and function and check whether these structures are similar to those described for other genera of the Gentianaceae and other families of the Gentianales. Samples of leaves at different developmental stages were collected and processed for anatomical and histochemical analysis using light microscopy and scanning electron microscopy. Colleters in M. obtusifolia have a protodermal origin, are of standard type, and are not vascularized. Young colleters are translucent and produce an abundant amount of sticky secretion. Later, they turn yellowish with a blackened region at the apex of the head, and the secretion, composed of polysaccharides and proteins, becomes less abundant and brownish. During senescence, the process begins with complete degradation and cell collapse of the secretory portion. The colleters of the standard type in M. obtusifolia have been observed for the first time in the Gentianaceae and represent additional evidence that reinforces how common this type of colleter is in the Gentianales. Such results provide new information on the anatomy, ontogeny, histochemistry, and colleter types of Gentianaceae.

scholarly journals Divalent Cations and Redox Conditions Regulate the Molecular Structure and Function of Visinin-Like Protein-1

PLoS ONE ◽  
2011 ◽  
Vol 6 (11) ◽  
pp. e26793 ◽  
Author(s):  
Conan K. Wang ◽  
Anne Simon ◽  
Christian M. Jessen ◽  
Cristiano L. P. Oliveira ◽  
Lynsey Mack ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Divalent Cations ◽  
Structure And Function ◽  
Redox Conditions ◽  
And Function ◽  
Molecular Structure And Function

scholarly journals Tungstoenzymes: Occurrence, Catalytic Diversity and Cofactor Synthesis

Inorganics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 44
Author(s):  
Carola S. Seelmann ◽  
Max Willistein ◽  
Johann Heider ◽  
Matthias Boll
Keyword(s):  
Abc Transporter ◽  
Aromatic Compounds ◽  
Metal Binding ◽  
Active Sites ◽  
Structure And Function ◽  
Hydration Reaction ◽  
Dimethyl Sulfoxide Reductase ◽  
Reduction Of Co2 ◽  
And Function ◽  
Electron Transfers

Tungsten is the heaviest element used in biological systems. It occurs in the active sites of several bacterial or archaeal enzymes and is ligated to an organic cofactor (metallopterin or metal binding pterin; MPT) which is referred to as tungsten cofactor (Wco). Wco-containing enzymes are found in the dimethyl sulfoxide reductase (DMSOR) and the aldehyde:ferredoxin oxidoreductase (AOR) families of MPT-containing enzymes. Some depend on Wco, such as aldehyde oxidoreductases (AORs), class II benzoyl-CoA reductases (BCRs) and acetylene hydratases (AHs), whereas others may incorporate either Wco or molybdenum cofactor (Moco), such as formate dehydrogenases, formylmethanofuran dehydrogenases or nitrate reductases. The obligately tungsten-dependent enzymes catalyze rather unusual reactions such as ones with extremely low-potential electron transfers (AOR, BCR) or an unusual hydration reaction (AH). In recent years, insights into the structure and function of many tungstoenzymes have been obtained. Though specific and unspecific ABC transporter uptake systems have been described for tungstate and molybdate, only little is known about further discriminative steps in Moco and Wco biosynthesis. In bacteria producing Moco- and Wco-containing enzymes simultaneously, paralogous isoforms of the metal insertase MoeA may be specifically involved in the molybdenum- and tungsten-insertion into MPT, and in targeting Moco or Wco to their respective apo-enzymes. Wco-containing enzymes are of emerging biotechnological interest for a number of applications such as the biocatalytic reduction of CO2, carboxylic acids and aromatic compounds, or the conversion of acetylene to acetaldehyde.

Memoirs: On Ptychodera flava, Eschscholtz

1897 ◽  
Vol s2-40 (157) ◽  
pp. 165-184
Author(s):  
ARTHUR WILLEY
Keyword(s):  
Living Condition ◽  
Structure And Function ◽  
The Other ◽  
Detailed Structure ◽  
Pharyngeal Wall ◽  
Littoral Habitat ◽  
Collar Region ◽  
Ptychodera Flava ◽  
And Function ◽  
First Time

1. This is the first time that an Enteropneust with a free pharynx has been studied in the living condition. 2. The Ptychodera flava of Eschscholtz (char. emend. mihi) is rightly assigned by Spengel to his amended genus Ptychodera, as shown by the presence of the genital pleura, of external liver saccules, and by the length of the collar region. 3. P. flava belongs to Spengel's sub-genus Chlamydothorax, as shown by the ventral origin of the genital pleura, the diffuse gonads, and the free pharynx. 4. In the fact of the gill-slits being open directly to the exterior throughout their entire length, P. flava is more closely related to P. bahamensis than to any other described species. This is also indicated by the simple rows of paired liver saccules as opposed to the irregular multiple arrangement met with in P. erythræa. 5. The genus Ptychodera. (referring more especially to the sub-genus Chlamydothorax) probably represents an archaic type, as shown by the diffuse arrangement of the gonads, the free pharynx, and its littoral habitat; and it is probably not, as Spengel supposes it to be, phylogenetically younger than the other genera of Enteropneusta. 6. The gill-slits, branchial skeleton, and the temporary atrium formed by the apposition of the genital pleura in Ptychodera, offer a general homology to the corresponding structures in Amphioxus and the Ascidians, while presenting many differences in the details of their structure and relations. 7. Some of these differences are comparatively unimportant, and such as might well be expected to occur in distantly related forms with such totally different habits of existence, while others are to be accounted for by a wide interpretation of the principle of correlation between structure and function. 8. Many differences of detailed structure in the pharyngeal wall and its skeletal supports between the Enteropneusta and Amphioxus are to be correlated with the fact that, in the former, the tongue-bars are larger (often, as in P. flava, very much larger) than the primary bars, while in the latter the reverse condition obtains.

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