scholarly journals Chemical and physical properties of an arabinogalactan-peptide from wheat endosperm

1974 ◽  
Vol 139 (3) ◽  
pp. 535-545 ◽  
Author(s):  
G. B. Fincher ◽  
W. H. Sawyer ◽  
B. A. Stone
Keyword(s):  
Optical Rotation ◽  
Subcellular Location ◽  
Successive Treatment ◽  
Partial Acid Hydrolysis ◽  
Wheat Endosperm ◽  
Anomeric Configuration ◽  
Molecular Core ◽  
Tentative Model ◽  
And Function ◽  
Hydrolysis Of

1. An arabinogalactan-peptide from wheat endosperm was studied by using physicochemical techniques and some aspects of its chemical structure were determined. 2. The arabinogalactan-peptide is a non-associating, polydisperse macromolecule ([unk]=22000) which exhibits only minor non-ideal effects in aqueous solution. 3. Examination of the products of partial acid hydrolysis of the polysaccharide component showed that arabinose is present in the α-l-arabinofuranosyl configuration, and i.r.-absorption spectroscopy and optical-rotation studies suggest that the d-galactopyranose residues are linked by glycosidic linkages in the β-anomeric configuration. 4. The arabinogalactan is linked to a peptide which represents 8% (w/w) of the arabinogalactan-peptide and which may be present as a molecular core. Partial degradation of the polymer by successive treatment with oxalic acid and NaOH showed that the linkage between polysaccharide and peptide involves galactose and hydroxyproline residues and is glycosidic in nature. A tentative model is proposed for the structure of the wheat endosperm arabinogalactan-peptide. 5. The subcellular location and function of the arabinogalactan-peptide is discussed in relation to previous work with related molecules.

scholarly journals The stereochemical course of reactions catalysed by the cellobiohydrolases produced by Talaromyces emersonii

1992 ◽  
Vol 283 (1) ◽  
pp. 31-34 ◽  
Author(s):  
M M Brooks ◽  
M G Tuohy ◽  
A V Savage ◽  
M Claeyssens ◽  
M P Coughlan
Keyword(s):  
Degradation Product ◽  
Proteolytic Degradation ◽  
Substrate Specificities ◽  
Talaromyces Emersonii ◽  
Anomeric Configuration ◽  
Culture Filtrates ◽  
Apparent Homogeneity ◽  
Displacement Reactions ◽  
Hydrolysis Of

Three forms of exocellobiohydrolase (EC 3.2.1.91), CBH IA, CBH IB and CBH II, were isolated to apparent homogeneity from culture filtrates of the aerobic fungus Talaromyces emersonii. CBH IA and CBH II appear to be native forms of these enzymes, while CBH IB may represent a proteolytic degradation product of the CBH IA enzyme. The hydrolysis of beta-cellobiosyl fluoride by each form was monitored by 1H-n.m.r. spectroscopy. The reactions catalysed by CBH IA and CBH IB proceed with retention of the anomeric configuration, whereas that catalysed by CBH II is one of inversion. Thus one may deduce that CBH IA (or CBH IB) and CBH II operate double and single displacement reactions respectively during catalysis of substrate. On the basis of these findings and the observed substrate specificities of the various forms, one may conclude that CBH IA (and CBH IB) is a family C enzyme, while CBH II belongs to family B [Henrissat, Claeyssens, Tomme, Lemesle & Mornon (1989) Gene 81, 83-95].

scholarly journals THE INTERRELATION OF THE SURVIVING HEART AND PANCREAS OF THE DOG IN SUGAR METABOLISM

1917 ◽  
Vol 26 (5) ◽  
pp. 721-744 ◽  
Author(s):  
Admont H. Clark
Keyword(s):  
Optical Rotation ◽  
Reducing Power ◽  
Sugar Metabolism ◽  
Weak Acid ◽  
Perfused Pancreas ◽  
Melting Points ◽  
Optical Rotations ◽  
Normal Utilization ◽  
Hydrolysis Of ◽  
Reducing Properties

When the pancreas of a dog is perfused aseptically with a Locke's solution containing dextrose in physiological concentrations, the optical rotation of the perfusate is diminished, but its reducing power is unaltered. This change also occurs if dextrose is added to a sugarfree pancreatic perfusate and the mixture incubated. These perfusates yield osazones with lower melting points than glucosazone, but when the perfusates are hydrolyzed with weak acid their optical, rotations and the melting points of their osazones are increased. These changes do not occur with levulose, or with an extract of the pancreas and dextrose. When the heart, spleen, or kidneys are perfused with dextrose solutions hydrolysis of the perfusates does not increase their optical rotation or power of reduction. When a pancreatic perfusate containing dextrose is circulated through a living heart not only do the above changes take place but, in addition, the reducing properties of the perfusate are altered. Hydrolysis of such a perfusate increases its reducing power, its optical rotation, and the melting point of its osazone. A heart does not cause this effect either alone or when perfused together with the spleen or kidneys. Levulose perfused through the heart and pancreas is unchanged. These phenomena are believed to be due to an enzyme or enzymes obtained from the perfused pancreas. The changes in optical rotation, in reduction, and in the osazones are accounted for by different degrees of dextrose condensation. While the living heart can destroy both dextrose and levulose to some extent, the experimental results suggest that the enzyme or enzymes derived from the perfused pancreas have a specific action on dextrose and are responsible for certain essential steps by which dextrose is prepared for normal utilization.

Phosphopeptides Obtained by Partial Acid Hydrolysis of α-Casein2

1957 ◽  
Vol 79 (10) ◽  
pp. 2559-2565 ◽  
Author(s):  
N. J. Hipp ◽  
M. L. Groves ◽  
T. L. McMeekin
Keyword(s):  
Acid Hydrolysis ◽  
Partial Acid Hydrolysis ◽  
Hydrolysis Of

scholarly journals Hatsusamides A and B: Two New Metabolites Produced by the Deep-Sea-Derived Fungal Strain Penicillium steckii FKJ-0213

Marine Drugs ◽  
2020 ◽  
Vol 18 (10) ◽  
pp. 513
Author(s):  
Hirotaka Matsuo ◽  
Rei Hokari ◽  
Aki Ishiyama ◽  
Masato Iwatsuki ◽  
Mayuka Higo ◽  
...  
Keyword(s):  
Optical Rotation ◽  
Hybrid Structure ◽  
Culture Broth ◽  
Nmr Data ◽  
1H Nuclear Magnetic Resonance ◽  
Ic50 Values ◽  
Hela S3 ◽  
Hydrolysis Of ◽  
Fcr3 Strain ◽  
New Metabolites

Two new nitrogen-containing metabolites, designated hatsusamide A (1) and B (2), were isolated from a culture broth of Penicilliumsteckii FKJ-0213 together with the known compounds tanzawaic acid B (3) and trichodermamide C (4) by physicochemical (PC) screening. The structures of 1 and 2 were determined as a tanzawaic acid B-trichodermamide C hybrid structure and a new analog of aspergillazines, respectively. The absolute configuration of 1 was determined by comparing the values of tanzawaic acid B and trichodermamide C in the literatures, such as 1H-nuclear magnetic resonance (1H-NMR) data and optical rotation, after hydrolysis of 1. Compounds 1–4 were evaluated for cytotoxicity and anti-malarial activities. Compounds 1 and 3 exhibited weak anti-malarial activity at half-maximal inhibitory concentration (IC50) values of 27.2 and 78.5 µM against the K1 strain, and 27.9 and 79.2 µM against the FCR3 strain of Plasmodium falciparum, respectively. Furthermore, 1 exhibited cytotoxicity against HeLa S3, A549, Panc1, HT29 and H1299 cells, with IC50 values of 15.0, 13.7, 12.9, 6.8, and 18.7 μM, respectively.

scholarly journals Mitochondria-specific photoactivation to monitor local sphingosine metabolism and function

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Suihan Feng ◽  
Takeshi Harayama ◽  
Sylvie Montessuit ◽  
Fabrice PA David ◽  
Nicolas Winssinger ◽  
...  
Keyword(s):  
Time Course ◽  
Random Distribution ◽  
Direct Evidence ◽  
Subcellular Location ◽  
Sphingolipid Metabolism ◽  
Powerful Approach ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases ◽  
And Function ◽  
Caged Molecules

Photoactivation ('uncaging’) is a powerful approach for releasing bioactive small-molecules in living cells. Current uncaging methods are limited by the random distribution of caged molecules within cells. We have developed a mitochondria-specific photoactivation method, which permitted us to release free sphingosine inside mitochondria and thereafter monitor local sphingosine metabolism by lipidomics. Our results indicate that sphingosine was quickly phosphorylated into sphingosine 1-phosphate (S1P) driven by sphingosine kinases. In time-course studies, the mitochondria-specific uncaged sphingosine demonstrated distinct metabolic patterns compared to globally-released sphingosine, and did not induce calcium spikes. Our data provide direct evidence that sphingolipid metabolism and signaling are highly dependent on the subcellular location and opens up new possibilities to study the effects of lipid localization on signaling and metabolic fate.

scholarly journals Synergistic control of Ca2+ mobilization in permeabilized mouse L1210 lymphoma cells by inositol 2,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate

1990 ◽  
Vol 271 (2) ◽  
pp. 549-553 ◽  
Author(s):  
P J Cullen ◽  
R F Irvine ◽  
A P Dawson
Keyword(s):  
Inositol Phosphate ◽  
Lymphoma Cells ◽  
Partial Acid Hydrolysis ◽  
Discernible Effect ◽  
Low Threshold ◽  
High Doses ◽  
Hydrolysis Of ◽  
Higher Doses ◽  
Subsequent Addition ◽  
Gain Access

L1210 lymphoma cells were permeabilized with digitonin, and the ability of Ins(2,4,5)P3 and Ins(1,3,4,5)P4 to mobilize intracellular Ca2+ was studied. At high doses of Ins(2,4,5)P3 Ca2+ was rapidly released from intracellular stores, and prior or subsequent addition of Ins(1,3,4,5)P4 had no discernible effect. However, the Ca2(+)-mobilizing action of low (threshold or just above) concentrations of Ins(2,4,5)P3 was markedly enhanced by Ins(1,3,4,5)P4, which alone caused no mobilization of Ca2+; this phenomenon was shown not to be due to protection of Ins(2,4,5)P3 by the Ins(1,3,4,5)P4 against hydrolysis. The ability of the pre-addition of Ins(1,3,4,5)P4 to enhance subsequent Ins(2,4,5)P3-induced Ca2+ mobilization was always seen whether or not the free Ca2+ concentration was low (pCa = 7) or high (pCa = 6). However, at low Ca2+, Ins(1,3,4,5)P4 could cause a further mobilization if added after the Ins(2,4,5)P3, whereas at higher Ca2+ values Ins(1,3,4,5)P4 was only able to affect Ca2+ if added before Ins(2,4,5)P3. These effects of Ins(1,3,4,5)P4 were not, at the same concentration, mimicked by a random mixture of InsP4 isomers obtained by partial acid hydrolysis of phytic acid, by Ins(1,3,4)P3 or by Ins(1,3,4,5,6)P5, and they were shown not to be due to enzymic generation of Ins(1,4,5)P3 from Ins(1,3,4,5)P4 by (a) the absence of any detectable production of Ins(1,4,5)P3 if radiolabelled Ins(1,3,4,5)P4 was used, or (b) the observation that Ins(1,3,4,5,6)P5 could mimic Ins(1,3,4,5)P4 provided that higher doses were used; this inositol phosphate, when added radiolabelled, yielded only trace quantities of D/L-Ins(1,4,5,6)P4, which itself does not mobilize Ca2+. We interpret these results overall to mean that in these cells there is a small proportion of the Ins(2,4,5)P3-mobilizable Ca2+ pools which can only be mobilized in the presence of Ins(1,3,4,5)P4 [or at the least, Ins(1,3,4,5)P4 can help Ins(2,4,5)P3 to gain access to them]. The significance of this conclusion is discussed in the light of current concepts of the second messenger function of Ins(1,3,4,5)P4.

THE PREPARATION OF L-α-GLYCERYLPHOSPHORYLCHOLINE FROM LECITHINS

1955 ◽  
Vol 33 (5) ◽  
pp. 761-766 ◽  
Author(s):  
N. H. Tattrie ◽  
C. S. McArthur
Keyword(s):  
Cadmium Chloride ◽  
Inorganic Salt ◽  
Optical Rotation ◽  
Chloride Complex ◽  
Ion Exchange Resins ◽  
Aqueous Alcohol ◽  
Synthetic Compound ◽  
Exchange Resins ◽  
Hydrolysis Of ◽  
Crude Lecithin

Investigation of the hydrolysis of phosphatidylcholines (lecithins) in hot aqueous alcohol under the influence of mercuric chloride has shown that glycerylphosphorylcholine is formed and that neither racemization nor migration of the phosphorylcholine moiety occurs. The fatty acids are split off much more rapidly than is choline and as a consequence appreciable amounts of glycerylphosphorylcholine are formed. On the basis of these observations a procedure was devised for the hydrolysis of crude lecithin and the isolation of glycerylphosphorylcholine in a yield of 69%. The product was identified as L-α-glycerylphosphorylcholine by analysis of its cadmium chloride complex, and comparison of its optical rotation with that of the synthetic compound of known configuration. Recovery of the diester from this complex was accomplished through removal of the inorganic salt by ion-exchange resins and the free L-α-glycerylphosphorylcholine was crystallized from 99% ethanol.

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