ABSTRACT
The cell nucleus plays a key role in differentiation processes in eukaryotic cells. It is not the nucleus in particular, but the organization of the genes and their remodeling that provides the data for the adjustments to be made according to the medium. The neutrophil nucleus has a different morphology. It is a multi-lobed nucleus where some researchers argue no longer function. However, studies indicate that it is very probable the occurrence of chromatin remodeling during activation steps. It may be that the human neutrophil nucleus also contributes to the mobility of neutrophils through thin tissue spaces. Questions like these will be discussed in this small review. The topics include morphology of human neutrophil nucleus, maturation process and modifications of the neutrophil nucleus, neutrophil activation and chromatin modifications, causes and consequences of multi-lobulated segmented morphology, and importance of the nucleus in the formation of neutrophil extracellular traps (NETs).
Subject(s)
Cell Nucleus/physiology , Neutrophils/physiology , Cell Differentiation , Cell Nucleus Shape , Chromatin Assembly and Disassembly , HumansABSTRACT
An endo-ß-1,4-xylanase (X22) was purified from crude extract of Emericella nidulans when cultivated on submerged fermentation using sugarcane bagasse as the carbon source. The purified protein was identified by mass spectrometry and was most active at pH and temperature intervals of 5.0-6.5 and 50-60°C, respectively. The enzyme showed half-lives of 40, 10 and 7 min at 28, 50 and 55°C, respectively, and pH 5.0. Apparent Km and Vmax values on soluble oat spelt xylan were 3.39 mg/mL and 230.8 IU/mg, respectively, while Kcat and Kcat/Km were 84.6 s(-1) and 25.0 s(-1) mg(-1) mL. Incubation with phenolic compounds showed that tannic acid and cinnamic acid had an inhibitory effect on X22 but no time-dependent deactivation. On the other hand, ferulic acid, 4-hydroxybenzoic acid, vanillin and p-coumaric acid did not show any inhibitory effect on X22 activity, although they changed X22 apparent kinetic parameters. Ethanol remarkably increased enzyme thermostability and apparent Vmax and Kcat values, even though the affinity and catalytic efficiency for xylan were lowered.
Subject(s)
Emericella/enzymology , Endo-1,4-beta Xylanases/isolation & purification , Endo-1,4-beta Xylanases/metabolism , Ethanol/pharmacology , Lignin/antagonists & inhibitors , Benzaldehydes/metabolism , Cellulose , Cinnamates/pharmacology , Coumaric Acids/metabolism , Endo-1,4-beta Xylanases/antagonists & inhibitors , Endo-1,4-beta Xylanases/chemistry , Enzyme Stability , Fermentation , Hydrogen-Ion Concentration , Kinetics , Parabens/metabolism , Propionates , Saccharum/metabolism , Substrate Specificity , Tannins/pharmacologyABSTRACT
A fibrino(geno)lytic nonhemorrhagic metalloproteinase (BleucMP) was purified from Bothrops leucurus snake venom by two chromatographic steps procedure on DEAE-Sephadex A-25 followed by CM-Sepharose Fast Flow column. BleucMP represented 1.75% (w/w) of the crude venom and was homogeneous on SDS-PAGE. BleucMP analyzed by MALDI TOF/TOF, showed a molecular mass of 23,057.54Da and when alkylated and reduced, the mass is 23,830.40Da. Their peptides analyzed in MS (MALDI TOF\TOF) showed significant score when compared with those of other proteins by NCBI-BLAST2 alignment display. As regards their proteolytic activities, BleucMP efficiently acted on fibrinogen, fibrin, and was inhibited by EDTA and 1.10-phenanthroline. This enzyme was also able to decrease significantly the plasma fibrinogen level provoking blood incoagulability, however was devoid of hemorrhagic activity when tested in the mice skin and did not induce relevant biochemical, hematological and histopathological alterations in mice. The aspects addressed in this paper provide data on the effect of BleucMP in envenomation from B. leucurus snakes in order to better understand the effects caused by snake venom metalloproteinase.