scholarly journals Functional and structural characterization of the myoglobin from the polychaete Ophelia bicornis

2005 ◽  
Vol 389 (2) ◽  
pp. 497-505 ◽  
Author(s):  
M. Teresa Sanna ◽  
Barbara Manconi ◽  
Massimo Castagnola ◽  
Bruno Giardina ◽  
Daniela Masia ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
Sperm Whale ◽  
Protein Sequencing ◽  
Oxygen Binding ◽  
Amino Acid Residues ◽  
Experimental Conditions ◽  
The Stability ◽  
Sperm Whale Myoglobin

The myoglobin of the polychaete annelid Ophelia bicornis was isolated, purified to homogeneity and characterized. The primary structure, obtained from cDNA and protein sequencing, consists of 139 amino acid residues. The alignment with other globin sequences showed that O. bicornis myoglobin misses the pre-A helix and the first six residues of the A helix. The presence of a PheB10-GlnE7 haem distal residue pair is in agreement with the measured oxygen affinity (P50=0.85 mmHg; 1 mmHg=0.133 kPa) and the only slightly higher autoxidation rate constant (0.28 h−1) with respect to that of the sperm whale myoglobin mutant E7 His→Gln (0.21 h−1) and to elephant myoglobin (0.1 h−1). Oxygen-binding co-operativity was found to be absent under all the examined experimental conditions. The resistance of O. bicornis myoglobin towards autoxidation seems to confirm the important role of part of the A helix in the stability of the globin. The higher pKa of the acid–alkaline ferric transition of O. bicornis with respect to Asian elephant myoglobin, as well as the higher absorbance ratio of its ferric form to the oxy form measured in the Soret region (γmet/γoxy) with respect to that of the African elephant myoglobin, suggested a stronger interaction between the distal glutamine and the water molecule at the sixth co-ordinate position.

Structural and functional characterization of sperm whale myoglobin mutants: Role of arginine (E10) in ligand stabilization

Biochemistry ◽  
1993 ◽  
Vol 32 (23) ◽  
pp. 6041-6049 ◽  
Author(s):  
Carlo Travaglini Allocatelli ◽  
Francesca Cutruzzola ◽  
Andrea Brancaccio ◽  
Maurizio Brunori ◽  
Jun Qin ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Sperm Whale ◽  
Ligand Stabilization ◽  
Sperm Whale Myoglobin

scholarly journals Engineering Ascaris hemoglobin oxygen affinity in sperm whale myoglobin: role of tyrosine B10

FEBS Letters ◽  
1994 ◽  
Vol 352 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Carlo Travaglini Allocatelli ◽  
Francesca Cutruzzolà ◽  
Andrea Brancaccio ◽  
Beatrice Vallone ◽  
Maurizio Brunori
Keyword(s):  
Oxygen Affinity ◽  
Sperm Whale ◽  
Hemoglobin Oxygen Affinity ◽  
Sperm Whale Myoglobin

scholarly journals Circe's haemoglobins, pig–human hybrids: functional characterization and structural considerations

1998 ◽  
Vol 335 (2) ◽  
pp. 211-216 ◽  
Author(s):  
Maria T. SANNA ◽  
Bruno GIARDINA ◽  
Mariagiuseppina PELLEGRINI ◽  
Alessandra OLIANAS ◽  
Irene MESSANA ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Structural Properties ◽  
Functional Properties ◽  
Functional Characterization ◽  
Oxygen Affinity ◽  
Oxygen Binding ◽  
Β Chain

We report the isolation and the functional characterization of α and β chains from pig (Sus scropha domesticus) haemoglobin, as well as of the pig–human hybrid haemoglobins, α2hβ2p and α2pβ2h (i.e. Circe's haemoglobins), obtained by mixing the purified α and β pig chains respectively with the corresponding partner human chains. Their functional properties have been compared with those of both parental haemoglobins in order to obtain information on the role of the different subunits and of their inter-relationships, both at the structural and functional levels. The results indicate that the functional properties of both hybrids are closer to those of the parental haemoglobin that provides the β chains, confirming the major role of the β chains in determining the oxygen affinity and the modulation mechanisms of the tetrameric molecule. This is supported by the thermodynamic properties, since the very low ΔH of oxygen binding that characterizes pig haemoglobin and the α2hβ2p hybrid haemoglobin may be taken as the reflection of specific structural properties of pig β chain.

scholarly journals The role of Val68(E11) in ligand binding to sperm whale myoglobin. Site-directed mutagenesis of a synthetic gene.

1990 ◽  
Vol 265 (20) ◽  
pp. 11788-11795
Author(s):  
K D Egeberg ◽  
B A Springer ◽  
S G Sligar ◽  
T E Carver ◽  
R J Rohlfs ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Sperm Whale ◽  
Site Directed Mutagenesis ◽  
Synthetic Gene ◽  
Directed Mutagenesis ◽  
Sperm Whale Myoglobin

scholarly journals Characterization of COMMD protein–protein interactions in NF-κB signalling

2006 ◽  
Vol 398 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Prim de Bie ◽  
Bart van de Sluis ◽  
Ezra Burstein ◽  
Karen J. Duran ◽  
Ruud Berger ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Copper Metabolism ◽  
Nuclear Factor Κb ◽  
Inhibitory Effect ◽  
Protein Family ◽  
Amino Acid Residues ◽  
Protein Protein Interactions ◽  
Necrosis Factor

COMMD [copper metabolism gene MURR1 (mouse U2af1-rs1 region 1) domain] proteins constitute a recently identified family of NF-κB (nuclear factor κB)-inhibiting proteins, characterized by the presence of the COMM domain. In the present paper, we report detailed investigation of the role of this protein family, and specifically the role of the COMM domain, in NF-κB signalling through characterization of protein–protein interactions involving COMMD proteins. The small ubiquitously expressed COMMD6 consists primarily of the COMM domain. Therefore COMMD1 and COMMD6 were analysed further as prototype members of the COMMD protein family. Using specific antisera, interaction between endogenous COMMD1 and COMMD6 is described. This interaction was verified by independent techniques, appeared to be direct and could be detected throughout the whole cell, including the nucleus. Both proteins inhibit TNF (tumour necrosis factor)-induced NF-κB activation in a non-synergistic manner. Mutation of the amino acid residues Trp24 and Pro41 in the COMM domain of COMMD6 completely abolished the inhibitory effect of COMMD6 on TNF-induced NF-κB activation, but this was not accompanied by loss of interaction with COMMD1, COMMD6 or the NF-κB subunit RelA. In contrast with COMMD1, COMMD6 does not bind to IκBα (inhibitory κBα), indicating that both proteins inhibit NF-κB in an overlapping, but not completely similar, manner. Taken together, these data support the significance of COMMD protein–protein interactions and provide new mechanistic insight into the function of this protein family in NF-κB signalling.

scholarly journals Functional and Structural Characterization of a Novel Isoamylase from Ostreococcus tauri and Role of the N-Terminal Domain

2020 ◽  
Vol 14 (1) ◽  
pp. 1-11
Author(s):  
Nicolas Hedín ◽  
Julieta Barchiesi ◽  
Diego F. Gomez-Casati ◽  
María V. Busi
Keyword(s):  
Crystallization Process ◽  
Biochemical Characterization ◽  
Carbohydrate Binding ◽  
Amino Acid Residues ◽  
Photosynthetic Organisms ◽  
Ostreococcus Tauri ◽  
The Family ◽  
Almost All

Background: The debranching starch enzymes, isoamylase 1 and 2 are well-conserved enzymes present in almost all the photosynthetic organisms. These enzymes are involved in the crystallization process of starch and are key components which remove misplaced α-1,6 ramifications on the final molecule. Aim: In this work, we performed a functional and structural study of a novel isoamylase from Ostreococcus tauri. Methods: We identified conserved amino acid residues possibly involved in catalysis. We also identified a region at the N-terminal end that resembles a Carbohydrate Binding Domain (CBM), which is more related to the family CBM48, but has no spatial conservation of the residues involved in carbohydrate binding. Results: The cloning, expression and biochemical characterization of this N-terminal region confirmed that it binds to polysaccharides, showing greater capacity for binding to amylopectin rather than total starch or amylose. Conclusion: This module could be a variant of the CBM48 family or it could be classified within a new CBM family.

Sign in / Sign up

Export Citation Format

Share Document