β-D-1, 3 GLUCANASES IN FUNGI

1959 ◽  
Vol 5 (2) ◽  
pp. 173-185 ◽  
Author(s):  
Elwyn T. Reese ◽  
Mary Mandels
Keyword(s):  
Rhizopus Arrhizus ◽  
Common Occurrence ◽  
Shake Flasks ◽  
Sporotrichum Pruinosum ◽  
Hydrolysis Of

β-D-1,3 Glucanases are of common occurrence in fungi, being detected in the culture nitrates of 96% of the organisms tested in shake flasks and in the sporophores of six basidiomycetcs. The enzyme is constitutive. Basidiomycete QM 806 and Sporotrichum pruinosum QM 826 are excellent sources of β-D-1,3 glucanase of the exo-type giving glucose as the sole reducing product of laminarin hydrolysis. Rhizopus arrhizus QM 1032 produces a β-D-1,3 glucanase of the endo-type giving laminaribiose and higher oligosaccharides as the products of hydrolysis of β-D-1,3 glucans. By controlling the conditions of growth β-D-1,3 glucanases can be produced free of β-1,4 glucanase (cellulase).

Study of lipase-catalyzed hydrolysis of some monoterpene esters

2001 ◽  
Vol 47 (5) ◽  
pp. 397-403 ◽  
Author(s):  
T Chatterjee ◽  
B K Chatterjee ◽  
D K Bhattacharyya
Keyword(s):  
Enzymatic Hydrolysis ◽  
Kinetic Model ◽  
Time Dependence ◽  
Candida Rugosa ◽  
Rhizopus Arrhizus ◽  
Hydrolysis Kinetics ◽  
Experimental Conditions ◽  
Mucor Miehei ◽  
Catalytic Activities ◽  
Hydrolysis Of

Studies of the hydrolysis of bornyl, citronellyl, geranyl, and terpenyl acetates by commercially available lipases of Candida rugosa, Rhizopus arrhizus, and Mucor miehei are presented. The hydrolysis of these monoterpene esters is investigated at various temperatures and pHs, and the time dependence of the percentage of esters hydrolysed is studied. The catalytic activities of the lipases in hydrolysing the esters are compared and, overall, it is observed that under the experimental conditions used the nonspecific lipase from C. rugosa produces the highest yields of the monoterpene alcohols in comparison to the primary-ester specific lipases such as R. arrhizus and M. miehei. A rate kinetic model has been used to understand the time dependence of the yield of the product acid.Key words: enzymatic hydrolysis, kinetics, lipase, monoterpene esters.

scholarly journals Hydrolysis of polyesters by Rhizopus arrhizus lipase.

1986 ◽  
Vol 50 (5) ◽  
pp. 1323-1325 ◽  
Author(s):  
Yutaka TOKIWA ◽  
Tomoo SUZUKI ◽  
Kiyoshi TAKEDA
Keyword(s):  
Rhizopus Arrhizus ◽  
Rhizopus Arrhizus Lipase ◽  
Hydrolysis Of

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

Lattice imaging and pore structure of β ferric oxyhydroxide

1978 ◽  
Vol 36 (1) ◽  
pp. 264-265
Author(s):  
T. Baird ◽  
J.R. Fryer ◽  
S.T. Galbraith
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bulk Material ◽  
Model Structure ◽  
Bulk Crystals ◽  
Lattice Imaging ◽  
Thin Sections ◽  
Ferric Oxyhydroxide ◽  
Resolution Electron ◽  
Hydrolysis Of

Introduction Previously we had suggested (l) that the striations observed in the pod shaped crystals of β FeOOH were an artefact of imaging in the electron microscope. Contrary to this adsorption measurements on bulk material had indicated the presence of some porosity and Gallagher (2) had proposed a model structure - based on the hollandite structure - showing the hollandite rods forming the sides of 30Å pores running the length of the crystal. Low resolution electron microscopy by Watson (3) on sectioned crystals embedded in methylmethacrylate had tended to support the existence of such pores.We have applied modern high resolution techniques to the bulk crystals and thin sections of them without confirming these earlier postulatesExperimental β FeOOH was prepared by room temperature hydrolysis of 0.01M solutions of FeCl3.6H2O, The precipitate was washed, dried in air, and embedded in Scandiplast resin. The sections were out on an LKB III Ultramicrotome to a thickness of about 500Å.

Mitochondrial Changes in Cholestasis

1972 ◽  
Vol 30 ◽  
pp. 258-259
Author(s):  
F. G. Zaki
Keyword(s):  
Biliary Obstruction ◽  
Alcoholic Cirrhosis ◽  
Ultrastructural Changes ◽  
List Type ◽  
Common Occurrence ◽  
Extrahepatic Cholestasis ◽  
Mitochondrial Alteration ◽  
Extrahepatic Biliary Obstruction ◽  
Liver Biopsies ◽  
Mitochondrial Anomalies

Alterations of liver cell mitochondria represent pathologic phenomenon of a fundamental nature. Mitochondrial anomalies have been often described in association with cholestasis. In attempt to determine whether a given pattern of mitochondrial alteration has any correlation with the cause of cholestasis, liver biopsies were examined from 38 patients showing :a. extrahepatic cholestasis due to complete or partial extrahepatic biliary obstruction (8 cases proven at operation)b. intrahepatic cholestasis due to drugs (9 cases), viral hepatitis (6 cases) and alcoholic cirrhosis (15 cases).Mitochondria exhibiting ultrastructural changes due to aging or to the ‘wear and teart’ processes were not considered. In this study, the only profound and most prominent mitochondrial deformation was reported on basis of their common occurrence in randomly examined sections.

Elucidating cyclic AMP signaling in subcellular domains with optogenetic tools and fluorescent biosensors

2019 ◽  
Vol 47 (6) ◽  
pp. 1733-1747 ◽  
Author(s):  
Christina Klausen ◽  
Fabian Kaiser ◽  
Birthe Stüven ◽  
Jan N. Hansen ◽  
Dagmar Wachten
Keyword(s):  
Cyclic Amp ◽  
Adenosine Monophosphate ◽  
Adenylyl Cyclases ◽  
Temporal Precision ◽  
Fluorescent Biosensors ◽  
Subcellular Domains ◽  
Spatio Temporal ◽  
Hydrolysis Of ◽  
Shed Light ◽  
Cyclic Amp Signaling

The second messenger 3′,5′-cyclic nucleoside adenosine monophosphate (cAMP) plays a key role in signal transduction across prokaryotes and eukaryotes. Cyclic AMP signaling is compartmentalized into microdomains to fulfil specific functions. To define the function of cAMP within these microdomains, signaling needs to be analyzed with spatio-temporal precision. To this end, optogenetic approaches and genetically encoded fluorescent biosensors are particularly well suited. Synthesis and hydrolysis of cAMP can be directly manipulated by photoactivated adenylyl cyclases (PACs) and light-regulated phosphodiesterases (PDEs), respectively. In addition, many biosensors have been designed to spatially and temporarily resolve cAMP dynamics in the cell. This review provides an overview about optogenetic tools and biosensors to shed light on the subcellular organization of cAMP signaling.

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