Structure and Ultrastructure of the Tracheary Elements of Asplenium (Pteridophyta) from the “Yungas”, Argentina

IAWA Journal ◽  
2010 ◽  
Vol 31 (2) ◽  
pp. 227-240 ◽  
Author(s):  
María Luján Luna ◽  
Gabriela Elena Giudice ◽  
María Alejandra Ganem ◽  
Elías Ramón de la Sota
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Maturation Stage ◽  
Tracheary Elements ◽  
Transmission Electron ◽  
Pit Membrane ◽  
Membrane Hydrolysis ◽  
Structure And Ultrastructure ◽  
Scanning Electron

The structure of root and rhizome tracheary cells of Asplenium spp. (Filicales, Pteridophyta) growing in NW Argentina was studied using light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In all cases, tracheary cells consisted of tracheids with various facets, mainly with scalariform pitting. With SEM, intertracheary pit membranes appeared smooth and non porose in most cases. In some instances, porose or web-like to thread-like pit membranes were noticed in rhizome tracheids. Under TEM secondary walls displayed a smooth and uniform appearance. Pit membranes showed a variation in thickness in presumed association with their maturation stage. More mature tracheary cells showed pit membranes with a mesh-like aspect and visible openings or pores. These characteristics are attributed to pit membrane hydrolysis, which facilitates water transport among tracheary cells.

Characterization of an organic-solvent-stable elastase from Pseudomonas indica and its potential use in eggshell membrane hydrolysis

2019 ◽  
Vol 85 ◽  
pp. 156-163
Author(s):  
Takenaka Shinji ◽  
Yokoyama Moe ◽  
Kimura Yukihiro ◽  
Yamashita Yoko ◽  
Ashida Hitoshi
Keyword(s):  
Organic Solvent ◽  
Eggshell Membrane ◽  
Membrane Hydrolysis ◽  
Solvent Stable ◽  
Potential Use

Mechanism of clearance of dipeptides by perfused hindquarters: sarcolemmal hydrolysis of peptides

1990 ◽  
Vol 259 (4) ◽  
pp. E463-E469
Author(s):  
M. Raghunath ◽  
E. L. Morse ◽  
S. A. Adibi
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Plasma Membrane ◽  
Present Experiment ◽  
Hydrolase Activity ◽  
Net Uptake ◽  
Membrane Hydrolysis ◽  
Peptide Hydrolases ◽  
Hydrolysis Of ◽  
Sarcolemmal Vesicles

The objective of the present experiment was to investigate the mechanism of clearance of a load of dipeptides (10 mumols) by perfused hindquarters of rats. The clearance was progressive over 60 min and was significantly (P less than 0.01) greater for glycylleucine than for glycylglycine (99 vs. 58% disappearance from the medium). Insulin had no significant effect on clearance of these dipeptides but stimulated the net uptake of their constituent amino acids. Investigation of the fate of peptides considered resistant to membrane hydrolysis showed a modest (24%) clearance for glycylsarcosine but a substantial one (89%) for glycylproline. Investigation of hydrolysis by sarcolemmal vesicles of skeletal muscle showed hydrolase activity against glycylglycine and glycylleucine but none against glycylsarcosine and glycylproline. Investigation of hydrolysis in the medium previously used to perfuse hindquarters for 60 min showed considerable activity against glycylleucine and glycylproline but none against glycylglycine and glycylsarcosine. These activities were entirely abolished by p-hydroxymercuribenzoate, an inhibitor of cytoplasmic peptide hydrolases. In conclusion, our data show that the mechanism of clearance of dipeptides by the perfused hindquarters is largely by hydrolysis, and the site of this hydrolysis differs for different dipeptides; hydrolysis is mediated either by plasma membrane enzymes, cytoplasmic enzymes released into the medium, or a combination of both.

scholarly journals Kinetic Evaluation of Cell Membrane Hydrolysis during Apoptosis by Human Isoforms of Secretory Phospholipase A2

2010 ◽  
Vol 98 (3) ◽  
pp. 466a
Author(s):  
Jennifer Nelson ◽  
Erin Olson ◽  
Katalyn Griffith ◽  
Michael Streeter ◽  
Allan M. Judd ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Phospholipase A2 ◽  
Secretory Phospholipase A2 ◽  
Kinetic Evaluation ◽  
Secretory Phospholipase ◽  
Membrane Hydrolysis ◽  
Human Isoforms
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