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 ◽  
...  

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.

1999 ◽  
Vol 73 (1) ◽  
pp. 46-50 ◽  
Author(s):  
Seiji Hongo ◽  
Kanetsu Sugawara ◽  
Yasushi Muraki ◽  
Yoko Matsuzaki ◽  
Emi Takashita ◽  
...  

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.


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 ◽  
...  

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.


1997 ◽  
Vol 77 (2) ◽  
pp. 241-251 ◽  
Author(s):  
P. H. Robinson

Four multiparous Holstein dairy cows in mid-lactation were utilized in a 4 × 4 Latin square design experiment to measure the response in intestinal amino acid profiles to progressive substitution of blood meal for corn gluten meal as the protein supplement. In addition, the influence of these protein sources on rumen fermentation and digestion as well as forestomach bacterial growth and escape were compared with a diet supplemented with soybean meal, a rapidly rumen-degraded protein source. Cows were offered a mixed silage ration of alfalfa silage (79.8% of DM) and corn silage (20.2% of DM) twice daily. Cows were also offered mixed concentrate at 123% (DM:DM) of the mixed silage ration in six equal meals per day to provide soybean meal, corn gluten meal, blood meal or a combination of the latter two sources as the primary supplemental protein source. Rumen soluble non-ammonia N concentrations were higher in cows fed soybean meal and declined linearly as blood meal substituted for corn gluten meal in the concentrate. Forestomach disappearance of N tended (P = 0.09) to be higher for the cows fed soybean meal vs. all other diets, and tended (P = 0.09) to be higher with the combined corn gluten meal and blood meal diet vs. the diets containing either alone. The latter is consistent with higher forestomach digestion of DM and OM in cows fed the combined diet. Rumen pool sizes of most DM components were lower when cows were fed soybean meal and, with the exception of N pools, increased linearly as blood meal substituted for corn gluten meal. Duodenal flow of amino acid protein was lower when cows were fed soybean meal, due mainly to reduced bacterial flow, and was lowest for the combined diet within the corn gluten meal and blood meal diets. The amino acid profile of duodenal protein differed for 12 of 17 amino acids examined when cows were fed the soybean meal diet vs. the other diets, and 12 of 17 amino acids either increased or decreased linearly as blood meal substituted for corn gluten meal. Data reported here and by previous researchers suggest an associative effect of addition of corn gluten meal and blood meal to the diet which increased rumen degradation of dietary protein. These data also show that manipulating the dietary source of supplemental protein can influence the amino acid profile of duodenally delivered amino acid protein as well as indicate that the rate of rumen degradation of individual amino acids differs among protein sources. In this study, methionine, cystine and histidine appeared to be more rapidly degraded in corn gluten meal than in blood meal, whereas glutamic acid, proline, isoleucine, threonine and lysine were more rapidly degraded in blood meal. Key words: Dairy cow, rumen bacteria, amino acid


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jing Xu ◽  
Xin Liu ◽  
Liyu Luo ◽  
Liying Tang ◽  
Na Guo ◽  
...  

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.


Author(s):  
Mr Syahriati ◽  
Amran Laga ◽  
Mulyati M. Thahir ◽  
Dan Zaraswati Dwyana

‘<em>Chao teri</em>” is a traditional fermented fish product of South Sulawesi as produced from the fermentation process of fish-carbohydrate-salt. It has characteristic like pasta, light-brown, distinctive and unique flavor, slightly acidic and salty taste. It is generally consumed by the local community as a complement dish or used as a flavor enhancer. This research aimed to analyze the chemical components of traditional ‘<em>Chao teri</em>” includes pH, total lactic acid, protein and amino acid profile. These chemical components were very contributes to the formation of flavor for traditional ‘<em>Chao teri</em>”. The results of research are expected to be a reference for the industry to develop ‘<em>Chao teri</em>”products into seasonings. Chemical characteristics of traditional ‘<em>Chao teri</em>” after 2 weeks fermentation obtained pH 6.35, lactic acid 1.20% and protein 21.15%. The analysis of amino acids indicated that traditional ‘<em>Chao teri</em>” contains complete essential and non-essential amino acids. The type of dominant amino acid found in traditional ‘<em>Chao teri</em>”are glutamic acid, leucine, aspartic acid and lysine.


2011 ◽  
Vol 55 (9) ◽  
pp. 4352-4360 ◽  
Author(s):  
Hitoshi Yamashita ◽  
Haruyoshi Tomita ◽  
Takako Inoue ◽  
Yasuyoshi Ike

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.


2001 ◽  
Vol 281 (3) ◽  
pp. E565-E574 ◽  
Author(s):  
Michele Balage ◽  
Sandrine Sinaud ◽  
Magali Prod'Homme ◽  
Dominique Dardevet ◽  
Thomas C. Vary ◽  
...  

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.


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