Oxidative cross-linking of potato proteins by fungal laccases: Reaction kinetics and effects on the structural and functional properties

2021 ◽  
pp. 102723
Author(s):  
Mingqin Li ◽  
Salwa Karboune ◽  
Kelly Light ◽  
Selim Kermasha
Keyword(s):  
Reaction Kinetics ◽  
Functional Properties ◽  
Cross Linking ◽  
Fungal Laccases ◽  
Structural And Functional Properties

scholarly journals Influence of intramolecular cross-links on the molecular, structural and functional properties of PEGylated haemoglobin

2007 ◽  
Vol 402 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Tao Hu ◽  
Belur N. Manjula ◽  
Dongxia Li ◽  
Michael Brenowitz ◽  
Seetharama A. Acharya
Keyword(s):  
Functional Properties ◽  
Oxygen Affinity ◽  
Direct Consequence ◽  
Molecular Properties ◽  
Cross Linking ◽  
Hydrodynamic Drag ◽  
Cross Link ◽  
Central Cavity ◽  
Structural And Functional Properties ◽  
Cross Links

The influence of intramolecular cross-links on the molecular, structural and functional properties of PEGylated {PEG [poly(ethylene glycol)]-conjugated} haemoglobin has been investigated. The sites and the extent of PEGylation of haemoglobin by reductive alkylation are not influenced by the presence of an αα-fumaryl cross-link at Lys-99(α). The propylated hexaPEGylated cross-linked haemoglobin, (propyl-PEG5K)6-αα-Hb, exhibits a larger molecular radius and lower colloidal osmotic pressure than propylated hexaPEGylated non-cross-linked haemoglobin, (propyl-PEG5K)6-Hb. Perturbation of the haem microenvironment and the α1β2 interface by PEGylation of haemoglobin is reduced by intramolecular cross-linking. Sedimentation velocity analysis established that PEGylation destabilizes the tetrameric structure of haemoglobin. (Propyl-PEG5K)6-Hb and (propyl-PEG5K)6-αα-Hb sediment as stable dimeric and tetrameric molecules, respectively. The ββ-succinimidophenyl PEG-2000 cross-link at Cys-93(β) outside the central cavity also influences the molecular properties of haemoglobin, comparable to that by the αα-fumaryl cross-link within the central cavity. However, the influence of the two cross-links on the oxygen affinity of PEGylated haemoglobin are very distinct, indicating that the high oxygen affinity of PEGylated haemoglobin is not a direct consequence of the dissociation of the haemoglobin tetramers into dimers. αα-Fumaryl cross-linking is preferred to modulate both oxygen affinity and molecular properties of PEGylated haemoglobin, and cross-linking outside the central cavity could only modulate molecular properties of PEGylated haemoglobin. It is suggested that PEGylation induces a hydrodynamic drag on haemoglobin and this plays a role in the microcirculatory properties of PEGylated haemoglobin.

Structural and functional properties of Escherichia coli-derived nucleoplasmin A comparative study of recombinant and natural proteins

2001 ◽  
Vol 268 (6) ◽  
pp. 1739-1748
Author(s):  
Aitor Hierro ◽  
Jesus M. Arizmendi ◽  
Javier De Las Rivas ◽  
M. Angeles Urbaneja ◽  
Adelina Prado ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Comparative Study ◽  
Functional Properties ◽  
Structural And Functional Properties
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