Analysis of amino acids, proteins, carbohydrates and lipids in food by capillary electromigration methods: a review

2016 ◽  
Vol 8 (18) ◽  
pp. 3649-3680 ◽  
Author(s):  
Marcone A. L. de Oliveira ◽  
Brenda L. S. Porto ◽  
Carina de A. Bastos ◽  
Céphora M. Sabarense ◽  
Fernando A. S. Vaz ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Samples ◽  
Carbohydrate Analysis ◽  
Acid Protein ◽  
Amino Acid Protein

We review the literature covering the evolution of amino acid, protein, lipid and carbohydrate analysis in food samples by electromigration techniques over the last 20 years.

scholarly journals Influenza C Virus CM2 Protein Is Produced from a 374-Amino-Acid Protein (P42) by Signal Peptidase Cleavage

1999 ◽  
Vol 73 (1) ◽  
pp. 46-50 ◽  
Author(s):  
Seiji Hongo ◽  
Kanetsu Sugawara ◽  
Yasushi Muraki ◽  
Yoko Matsuzaki ◽  
Emi Takashita ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Matrix Protein ◽  
Signal Peptidase ◽  
M Gene ◽  
Recognition Motif ◽  
Acid Protein ◽  
Influenza C Virus ◽  
Amino Acid Protein

ABSTRACT Although unspliced mRNA from influenza C virus RNA segment 6 (M gene) has a single open reading frame capable of encoding a 374-amino-acid protein (Mr, 42,000), the major polypeptide synthesized from this mRNA species is the CM2 protein, with an Mr of 18,000. The present study was performed to investigate the mechanism by which CM2 is generated from the unspliced mRNA. It was reported previously that the 374-amino-acid protein (P42) is an integral membrane protein having two internal hydrophobic domains, one of which (residues 241 to 252) is followed by two sequences (252 Ile-Thr-Ser and 257 Ala-Ser-Ala) favorable for cleavage by signal peptidase. To examine the possibility that P42 is cleaved by signal peptidase after Ser residue 254 or Ala residue 259 to yield CM2, we constructed three mutated M gene cDNAs in which either or both of the two sequences were eliminated and tested their ability to synthesize CM2 in the transfected COS cells. The results showed that CM2 synthesis was blocked completely when the second recognition motif for signal peptidase was removed. It was also found that when the mRNA transcript of the wild-type M gene was translated in vitro, P42, but not CM2, was synthesized in the absence of dog pancreas microsomal membranes, whereas CM2, in addition to a polypeptide (designated M1′) slightly larger than matrix protein (M1), was synthesized in the presence of microsomes. When the same experiment was done with the transcript of the mutated M gene in which the second recognition motif was removed, synthesis of CM2 could not be seen, even in the presence of microsomes. From these results, we conclude that cleavage of P42 by signal peptidase after Ala residue 259 produces CM2, composed of the C-terminal 115 amino acids, in addition to M1′, composed of the N-terminal 259 amino acids.

scholarly journals A Metabonomics Investigation into the Therapeutic Effects of BuChang NaoXinTong Capsules on Reversing the Amino Acid-Protein Interaction Network of Cerebral Ischemia

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jing Xu ◽  
Xin Liu ◽  
Liyu Luo ◽  
Liying Tang ◽  
Na Guo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cerebral Ischemia ◽  
Protein Interaction ◽  
System Level ◽  
Enzyme Linked Immunosorbent Assay ◽  
Acid Decarboxylase ◽  
Therapeutic Effects ◽  
Acid Protein ◽  
Amino Acid Protein

Background. Amino acids (AAs) in cerebrospinal fluid (CSF) play a pivotal role in cerebral ischemia (CI). BuChang NaoXinTong Capsules (BNC) are widely prescribed in Chinese medicine for the treatment of cerebrovascular and cardiovascular diseases. Methods. In order to investigate the therapeutic effects and pharmacological mechanisms of BNC on reversing CI from a system level, an amino acid-protein interaction imbalanced network of CI containing metabolites of AAs, key regulatory enzymes, and proteins was constructed for the first time. Furthermore, a novel method for detecting the ten AAs in CSF was developed by UPLC-QQQ-MS in an effort to validate the imbalanced networks and the therapeutic effects of BNC via analysis of metabolites. Results. Based on a middle cerebral artery occlusion (MCAO) rat model, the dynamic levels of amino acids in CSF 3, 6, 12, and 24 h after MCAO were analyzed. Up to 24 h, the accumulated nine AA biomarkers were found to significantly change in the MCAO group compared to the sham group and exhibited an obvious tendency for returning to baseline values after BNC treatment. In addition, based on the imbalanced network of CI, four key enzymes that regulate the generation of BNC-mediated AA biomarkers were selected and validated using an enzyme-linked immunosorbent assay and western blotting. Finally, aromatic-L-amino-acid decarboxylase (AADC) was found to be one of the putative targets for BNC-mediated protection against CI. Conclusion. This study provides new strategies to explore the mechanism of cerebral ischemia and help discover the potential mechanism of BNC.

scholarly journals Preliminary Investigation to Review If a Glycomacropeptide Compared to L-Amino Acid Protein Substitute Alters the Pre- and Postprandial Amino Acid Profile in Children with Phenylketonuria

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2443 ◽  
Author(s):  
Anne Daly ◽  
Sharon Evans ◽  
Alex Pinto ◽  
Richard Jackson ◽  
Catherine Ashmore ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Preliminary Investigation ◽  
Insulin Response ◽  
Amino Acid Profile ◽  
Early Morning ◽  
Protein Substitute ◽  
Acid Protein ◽  
Urea Production ◽  
Amino Acid Protein

In Phenylketonuria (PKU), the peptide structure of the protein substitute (PS), casein glycomacropeptide (CGMP), is supplemented with amino acids (CGMP-AA). CGMP may slow the rate of amino acid (AA) absorption compared with traditional phenylalanine-free amino acids (Phe-free AA), which may improve nitrogen utilization, decrease urea production, and alter insulin response. Aim: In children with PKU, to compare pre and postprandial AA concentrations when taking one of three PS’s: Phe-free AA, CGMP-AA 1 or 2. Methods: 43 children (24 boys, 19 girls), median age 9 years (range 5–16 years) were studied; 11 took CGMP-AA1, 18 CGMP-AA2, and 14 Phe-free AA. Early morning fasting pre and 2 h postprandial blood samples were collected for quantitative AA on one occasion. A breakfast with allocated 20 g protein equivalent from PS was given post fasting blood sample. Results: There was a significant increase in postprandial AA for all individual AAs with all three PS. Postprandial AA histidine (p < 0.001), leucine (p < 0.001), and tyrosine (p < 0.001) were higher in CGMP-AA2 than CGMP-AA1, and leucine (p < 0.001), threonine (p < 0.001), and tyrosine (p = 0.003) higher in GCMP-AA2 than Phe-free AA. This was reflective of the AA composition of the three different PS’s. Conclusions: In PKU, the AA composition of CGMP-AA influences 2 h postprandial AA composition, suggesting that a PS derived from CGMP-AA may be absorbed similarly to Phe-free AA, but this requires further investigation.

scholarly journals Genetic Organization and Mode of Action of a Novel Bacteriocin, Bacteriocin 51: Determinant of VanA-Type Vancomycin-Resistant Enterococcus faecium

2011 ◽  
Vol 55 (9) ◽  
pp. 4352-4360 ◽  
Author(s):  
Hitoshi Yamashita ◽  
Haruyoshi Tomita ◽  
Takako Inoue ◽  
Yasuyoshi Ike
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Enterococcus Faecium ◽  
Promoter Sequence ◽  
Signal Peptidase ◽  
Start Codon ◽  
Content Type ◽  
Acid Protein ◽  
Vancomycin Resistant ◽  
Amino Acid Protein

ABSTRACTBacteriocin 51 (Bac 51) is encoded on the mobile plasmid pHY (6,037 bp), which was isolated from vancomycin-resistantEnterococcus faeciumVRE38. Bacteriocin 51 is active againstE. faecium,E. hirae, andE. durans. Sequence analysis of pHY showed that it encodes nine open reading frames (ORFs) from ORF1 to ORF9 (in that order). Genetic analysis suggested that ORF1 and ORF2, which were designatedbacAandbacB, respectively, are the bacteriocin and immunity genes.bacAencodes a 144-amino-acid protein. The deduced BacA protein has a typical signal sequence at its amino terminus, and a potential signal peptidase-processing site corresponding to the V-E-A sequence is located between the 37th and 39th amino acids. The predicted mature BacA protein consists of 105 amino acids. A potential promoter sequence was identified upstream of the start codon.bacBencodes a 55-amino-acid protein. No obvious promoter or terminator sequence was identified betweenbacAandbacB. Northern blot analysis ofbacAandbacBwith abacARNA probe produced a transcript of approximately 700 nucleotides, which corresponded to the combined nucleotide sizes ofbacAandbacB, indicating that transcription was initiated from the promoter upstream ofbacA, continued throughbacB, and was terminated at the terminator downstream ofbacB. The transcription start site was determined to be the T nucleotide located 6 nucleotides downstream from the −10 promoter sequence. These results indicate thatbacAandbacBconstitute an operon and thatbacAis the bacteriocin structural gene whilebacBis the immunity gene. The purified C-terminally His tagged BacA protein of Bac 51 showed bacteriostatic activity against the indicator strain. The purified C-terminally His tagged BacA protein of Bac 32 (whose mature BacA protein has 54 amino acids) and the culture filtrates of the Bac 31- and Bac 43-producingE. faecalisstrain FA2-2 showed bactericidal activity. Bac 31 and Bac 43 are pore-forming bacteriocins, unlike the newly characterized bacteriocin Bac 51.

scholarly journals Amino acids and insulin are both required to regulate assembly of the eIF4E · eIF4G complex in rat skeletal muscle

2001 ◽  
Vol 281 (3) ◽  
pp. E565-E574 ◽  
Author(s):  
Michele Balage ◽  
Sandrine Sinaud ◽  
Magali Prod'Homme ◽  
Dominique Dardevet ◽  
Thomas C. Vary ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Protein Meal ◽  
Acid Protein ◽  
Postprandial Insulin ◽  
Amino Acid Protein

The respective roles of insulin and amino acids in regulation of skeletal muscle protein synthesis and degradation after feeding were examined in rats fasted for 17 h and refed over 1 h with either a 25 or a 0% amino acid/protein meal. In each nutritional condition, postprandial insulin secretion was either maintained (control groups: C25 and C0) or blocked with diazoxide injections (diazoxide groups: DZ25 and DZ0). Muscle protein metabolism was examined in vitro in epitrochlearis muscles. Only feeding the 25% amino acid/protein meal in the presence of increased plasma insulin concentration (C25 group) stimulated protein synthesis and inhibited proteolysis in skeletal muscle compared with the postabsorptive state. The stimulation of protein synthesis was associated with increased phosphorylation of eukaryotic initiation factor (eIF)4E binding protein-1 (4E-BP1), reduced binding of eIF4E to 4E-BP1, and increased assembly of the active eIF4E · eIF4G complex. The p70 S6 kinase (p70S6k) was also hyperphosphorylated in response to the 25% amino acid/protein meal. Acute postprandial insulin deficiency induced by diazoxide injections totally abolished these effects. Feeding the 0% amino acid/protein meal with or without postprandial insulin deficiency did not stimulate muscle protein synthesis, reduce proteolysis, or regulate initiation factors and p70S6kcompared with fasted rats. Taken together, our results suggest that both insulin and amino acids are required to stimulate protein synthesis, inhibit protein degradation, and regulate the interactions between eIF4E and 4E-BP1 or eIF4G in response to feeding.

scholarly journals Characterization of the Gallate Dioxygenase Gene: Three Distinct Ring Cleavage Dioxygenases Are Involved in Syringate Degradation by Sphingomonas paucimobilis SYK-6

2005 ◽  
Vol 187 (15) ◽  
pp. 5067-5074 ◽  
Author(s):  
Daisuke Kasai ◽  
Eiji Masai ◽  
Keisuke Miyauchi ◽  
Yoshihiro Katayama ◽  
Masao Fukuda
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Terminal Region ◽  
Ring Cleavage ◽  
Sphingomonas Paucimobilis ◽  
Acid Protein ◽  
Demethylation Pathway ◽  
Dioxygenase Gene ◽  
Amino Acid Protein

ABSTRACT Sphingomonas paucimobilis SYK-6 converts vanillate and syringate to protocatechuate (PCA) and 3-O-methylgallate (3MGA) in reactions with the tetrahydrofolate-dependent O-demethylases LigM and DesA, respectively. PCA is further degraded via the PCA 4,5-cleavage pathway, whereas 3MGA is metabolized via three distinct pathways in which PCA 4,5-dioxygenase (LigAB), 3MGA 3,4-dioxygenase (DesZ), and 3MGA O-demethylase (LigM) are involved. In the 3MGA O-demethylation pathway, LigM converts 3MGA to gallate, and the resulting gallate appears to be degraded by a dioxygenase other than LigAB or DesZ. Here, we isolated the gallate dioxygenase gene, desB, which encodes a 418-amino-acid protein with a molecular mass of 46,843 Da. The amino acid sequences of the N-terminal region (residues 1 to 285) and the C-terminal region (residues 286 to 418) of DesB exhibited ca. 40% and 27% identity with the sequences of the PCA 4,5-dioxygenase β and α subunits, respectively. DesB produced in Escherichia coli was purified and was estimated to be a homodimer (86 kDa). DesB specifically attacked gallate to generate 4-oxalomesaconate as the reaction product. The Km for gallate and the V max were determined to be 66.9 ± 9.3 μM and 42.7 ± 2.4 U/mg, respectively. On the basis of the analysis of various SYK-6 mutants lacking the genes involved in syringate degradation, we concluded that (i) all of the three-ring cleavage dioxygenases are involved in syringate catabolism, (ii) the pathway involving LigM and DesB plays an especially important role in the growth of SYK-6 on syringate, and (iii) DesB and LigAB are involved in gallate degradation.

scholarly journals LASS3 (longevity assurance homologue 3) is a mainly testis-specific (dihydro)ceramide synthase with relatively broad substrate specificity

2006 ◽  
Vol 398 (3) ◽  
pp. 531-538 ◽  
Author(s):  
Yukiko Mizutani ◽  
Akio Kihara ◽  
Yasuyuki Igarashi
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Family Members ◽  
Fatty Acyl ◽  
Ceramide Synthase ◽  
Broad Substrate Specificity ◽  
Acid Protein ◽  
Amino Acid Protein

The LASS (longevity assurance homologue) family members are highly conserved from yeasts to mammals. Five mouse and human LASS family members, namely LASS1, LASS2, LASS4, LASS5 and LASS6, have been identified and characterized. In the present study we cloned two transcriptional variants of hitherto-uncharacterized mouse LASS3 cDNA, which encode a 384-amino-acid protein (LASS3) and a 419-amino-acid protein (LASS3-long). In vivo, [3H]dihydrosphingosine labelling and electrospray-ionization MS revealed that overproduction of either LASS3 isoform results in increases in several ceramide species, with some preference toward those having middle- to long-chain-fatty acyl-CoAs. A similar substrate preference was observed in an in vitro (dihydro)ceramide synthase assay. These results indicate that LASS3 possesses (dihydro)ceramide synthesis activity with relatively broad substrate specificity. We also found that, except for a weak display in skin, LASS3 mRNA expression is limited almost solely to testis, implying that LASS3 plays an important role in this gland.

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