scholarly journals Localization and interconversion of tetrahydropteroylglutamates in isolated pea mitochondria

1972 ◽  
Vol 128 (1) ◽  
pp. 29-40 ◽  
Author(s):  
M. T. Clandinin ◽  
E. A. Cossins
Keyword(s):  
Amino Acids ◽  
Free Amino ◽  
Lactobacillus Casei ◽  
Sucrose Density Gradient ◽  
Mitochondrial Fraction ◽  
C1 Metabolism ◽  
Isolated Mitochondria ◽  
Feeding Experiments ◽  
Pteroylglutamic Acid ◽  
Derivatives Of

1. Mitochondria were extracted from 4-day-old pea cotyledons and purified on a sucrose density gradient. 2. Microbiological assay of the purified mitochondrial fraction with Lactobacillus casei (A.T.C.C. 7469), Streptococcus faecalis (A.T.C.C. 8043) and Pediococcus cerevisiae (A.T.C.C. 8081) revealed a discrete pool of conjugated and unconjugated derivatives of tetrahydropteroylglutamic acid. 3. Solubilization and chromatographic studies of the mitochondrial fraction demonstrated the presence of formylated and methylated derivatives, 10-formyltetrahydropteroylmonoglutamic acid, 5-formyltetrahydropteroylmonoglutamic acid and 5-formyltetrahydropteroyldiglutamic acid being the major derivatives present. 4. The principal mitochondrial pteroylglutamates were labelled when dry seeds were allowed to imbibe [2-14C]pteroylglutamic acid and 5-[methyl-14C]-methyltetrahydropteroylmonoglutamic acid. 5. The ability of isolated mitochondria to catalyse oxidation and reduction of tetrahydropteroylglutamic acid derivatives was demonstrated in feeding experiments in which [14C]formaldehyde, [3-14C]serine, sodium [14C]formate, 5-[methyl-14C]methyltetrahydropteroylmonoglutamic acid or [2-14C]-glycine served as C1 donor. In addition,14C was incorporated into free amino acids related to C1 metabolism.

scholarly journals Pteroylglutamate derivatives in Pisum sativum L. Biosynthesis of cotyledonary tetrahydropteroylglutamates during germination

1971 ◽  
Vol 125 (1) ◽  
pp. 17-26 ◽  
Author(s):  
A. J. Roos ◽  
E. A. Cossins
Keyword(s):  
Pisum Sativum ◽  
Lactobacillus Casei ◽  
Deae Cellulose ◽  
Cellulose Synthesis ◽  
Feeding Experiments ◽  
Tissue Extracts ◽  
Pisum Sativum L ◽  
Pteroylglutamic Acid ◽  
Derivatives Of ◽  
Endogenous Enzymes

1. The concentrations of pteroylglutamate derivatives in the cotyledons of pea (Pisum sativum L.) seedlings were determined by microbiological assay by using Lactobacillus casei (A.T.C.C. 7469), Streptococcus faecalis (A.T.C.C. 8043) and Pediococcus cerevisiae (A.T.C.C. 8081). During germination the pteroylglutamate content of the cotyledons increased rapidly from 0.2μg/g dry wt. to 4.0μg/g dry wt., the maximum values being reached approx. 120h after imbibition. 2. Approx. 50% of the pteroylglutamate pool of 3-day-old seedlings was accounted for by highly conjugated derivatives. The concentrations of such derivatives were greatest when precautions were taken to inactivate endogenous enzymes before extraction of the tissues. 3. Individual derivatives present in the tissue extracts were separated by chromatography on DEAE-cellulose. Synthesis of the major derivative, 5-methyltetrahydropteroylmonoglutamate, was inhibited by administration of 0.1mm-aminopterin and -amethopterin solutions during imbibition. Under these conditions pteroylglutamic acid accumulated in the tissues. 4. Feeding experiments employing [2-14C]pteroylglutamic acid and 5[14C]-methyltetrahydro-pteroylmonoglutamic acid revealed that both compounds were incorporated into conjugated and unconjugated derivatives of the pteroylglutamate pool.

scholarly journals Physiological and molecular responses of a newly evolved auxotroph of Chlamydomonas to B12 deprivation

2019 ◽  
Author(s):  
Freddy Bunbury ◽  
Katherine E Helliwell ◽  
Payam Mehrshahi ◽  
Matthew P Davey ◽  
Deborah Salmon ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Amino Acids ◽  
Experimental Evolution ◽  
Free Amino ◽  
Oxygen Species ◽  
Term Survival ◽  
Molecular Responses ◽  
C1 Metabolism ◽  
Use Efficiency

AbstractThe corrinoid B12 is synthesised only by prokaryotes yet is widely required by eukaryotes as an enzyme cofactor. Microalgae have evolved B12 dependence on multiple occasions and we previously demonstrated that experimental evolution of the non-requiring alga Chlamydomonas reinhardtii in media supplemented with B12 generated a B12-dependent mutant (hereafter metE7). This clone provides a unique opportunity to study the physiology of a nascent B12 auxotroph. Our analyses demonstrate that B12 deprivation of metE7 disrupted C1 metabolism, caused an accumulation of starch and triacylglycerides and a decrease in photosynthetic pigments, proteins and free amino acids. B12 deprivation also caused a substantial increase in reactive oxygen species (ROS), which preceded rapid cell death. Surprisingly, survival could be improved without compromising growth by simultaneously depriving the cells of nitrogen, suggesting a type of cross protection. Significantly, we found further improvements in survival under B12 limitation and an increase in B12 use-efficiency after metE7 underwent a further period of experimental evolution, this time in coculture with a B12-producing bacterium. Therefore, although an early B12-dependent alga would likely be poorly adapted to B12 deprivation, association with B12-producers can ensure long-term survival whilst also providing the environment to evolve mechanisms to better tolerate B12 limitation.

scholarly journals Hepatic synthesis of carnitine from protein-bound trimethyl-lysine. Lysosomal digestion of methyl-lysine-labelled asialo-fetuin

1976 ◽  
Vol 160 (1) ◽  
pp. 85-95 ◽  
Author(s):  
J LaBadie ◽  
W A Dunn ◽  
N N Aronson
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Free Amino ◽  
Isolated Perfused Rat Liver ◽  
Methyl Groups ◽  
Second Derivative ◽  
Perfused Rat Liver ◽  
Lysine Residues ◽  
Derivatives Of ◽  
Hepatic Synthesis

The biosynthesis of carnitine in the rat was studied by following the metabolism of two radioactive derivatives of asialo-fetuin. The first contained 14C-labelled methyl groups covalently bound to the 6-N-amino fraction of its lysine residues as 6-N-monomethyl- and dimethyl-lysine. By treating this protein with iodomethane, a second derivative was produced in which the radioactivity was preferentially incorporated as 6-N-[Me-14C]-trimethyl-lysine. These desialylated glycoproteins, like other asialo-proteins, were immediately cleared from the blood by rat liver. Within hepatocyte lysosomes, the 14C-labelled proteins were rapidly hydrolysed, producing free amino acids containing the various 6-N-[Me-14C]methylated lysine residues. The radioactive amino acids crossed the lysosomal membrane and were further metabolized in the cytosol. Carnitine was the major radioactive metabolite detected in extracts of the rat carcass and liver after intravenous injection of 6-N-[Me-14C]trimethyl-lysine-labelled asialo-fetuin. Within 3h, at least 34.6% of the trimethyl-lysine in the administered protein was converted into carnitine. Similarly, an isolated perfused rat liver converted 30% of the added peptide-bound trimethyl-lysine into carnitine within 90 min. On the other hand, in numerous attempts we failed to detect radioactive carnitine in both rat liver and carcass between 20 min and 22 h after injection of 6-N-[Me-14C]-monomethyl- and -dimethyl-lysine-labelled asialo-fetuin. These data provide evidence for a pathway of carnitine biosynthesis that involves trimethyl-lysine as a peptide-bound precursor as proposed by R.A. Cox & C.L. Hoppel [(1973) Biochem. J. 136, 1083-1090] and V. Tanphaichitr & H.P. Broquist [(1973) J. Biol. Chem. 248, 2176-2181]. The findings also show that rat liver can synthesize carnitine without the aid of other tissues, but cannot convert free partially methylated lysines into trimethyl-lysine.

scholarly journals Contents of Functionally Bioactive Peptides, Free Amino Acids, and Biogenic Amines in Dutch-Type Cheese Models Produced with Different Lactobacilli

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5465
Author(s):  
Monika Garbowska ◽  
Antoni Pluta ◽  
Anna Berthold-Pluta
Keyword(s):  
Amino Acids ◽  
Biogenic Amines ◽  
Free Amino Acids ◽  
Free Amino ◽  
Lactobacillus Casei ◽  
Bioactive Peptides ◽  
Total Content ◽  
Biochemical Processes ◽  
Cheese Ripening ◽  
Cheese Model

Cheese ripening involves a number of biochemical processes, mainly of a proteolytic nature, which are initially triggered principally by milk-coagulating enzymes and, afterward, by microorganisms or enzymes of microbial origin. The proteolytic reactions affect, primarily, the synthesis of macro- and medium-molecular peptides from casein. In turn, the advanced proteolysis ends in the formation of short peptides and free amino acids. Further reactions may lead to the formation of nutritionally unfavorable biogenic amines. The present study aimed to determine changes in the contents of bioactive peptides (anserine and L-carnosine), free amino acids, and biogenic amines throughout the ripening of cheese models produced with the addition of Lactobacillus genus bacteria. The contents of amino acids varied considerably in the cheese models, depending on the bacterial strain added and ripening time. After five weeks of ripening, the total content of free amino acids in the cheese models ranged from 611.02 (a cheese model with Lactobacillus casei 2639) to 1596.64 mg kg−1 (a cheese model with Lb. acidophilus 2499). After the same time, the contents of the total biogenic amines in the cheese models with the addition of lactobacilli were lower than in the control cheese model (except for the model with Lb. rhamnosus 489). Anserine was detected in all cheese models (79.29–119.02 mg kg−1), whereas no L-carnosine was found over a five-week ripening period in the cheese models with Lb. delbrueckii 490 and Lb. casei 2639. After a five-week ripening, the highest total content of bioactive peptides was determined in the cheese models containing Lb. acidophilus 2499 (136.11 mg kg−1).

On the synthesis of 3,4-dihydroxyprolines. I. cis-Glycolation of 3,4-dehydroproline derivatives

1968 ◽  
Vol 21 (3) ◽  
pp. 769 ◽  
Author(s):  
CB Hudson ◽  
AV Robertson ◽  
WRJ Simpson
Keyword(s):  
Amino Acids ◽  
Carboxylic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Yields ◽  
Proline Derivatives ◽  
Derivatives Of

The interaction of OsO4 and protected derivatives of 3,4-dehydro-DL-proline gives high yields of 2,3-trans-3,4-cis-3,4-dihydroxy-DL-proline derivatives, with only traces of the 2,3-cis-3,4-cis diastereoisomers. Corresponding α-glycolation with KMnO4 gives mixtures of the 2,3-trans-3,4-cis and 2,3-cis-3,4-cis isomers in the ratio 1 : 1. Separation of the components of such mixtures is extremely difficult. The free amino acids in these two families of the 3,4-dihydroxy-DL-prolines have been characterized. Epimerization at C2 of 2,3-cis derivatives occurs readily. O-Tosylation of the 2,3-cis series occurs more readily than for other hydroxyprolines. Esters of N,O,O-tritosyl-2,3-trans-3,4-cis-3,4-dihydroxyproline are converted very rapidly by mild alkali into the equivalent esters of X-tosylpyrrole-2-carboxylic acid. For the corresponding N,O,O-tritosyl carboxylic acid, decarboxylation also takes place during aromatization, to yield N-tosylpyrrole.

scholarly journals Free amino acids and sugars in the flower of Carthamus tinctorius L.

2014 ◽  
Vol 56 (1) ◽  
pp. 107-117 ◽  
Author(s):  
Yoshiyuki Takahasi ◽  
Manabu Yukita ◽  
Mizu Wada ◽  
Masato Takahashi ◽  
Akiyoshi Fukushima ◽  
...  
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Carthamus Tinctorius ◽  
Gas Liquid Chromatography ◽  
Free Sugars ◽  
Alditol Acetate ◽  
Quantitative Analyses ◽  
Layer Chromatography ◽  
Derivatives Of

Qualitative and quantitative analyses of free amino acids and sugars in the extracts from freshly collected florets of <em>Carthamus tinctorius</em> L. were performed by combination of thin-layer chromatography (TLC), automatic amino acid analysis and gas-liquid chromatography (GLC). Sixteen amino acids were detected and their quantitative relations were investigated. Alditol acetate derivatives of free sugars were examined by GLC. The retention time and resolution pattern of the following monosaccharides, rhamnose, arabinose, xylose, mannose and glucose, were ultimately investigated.

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