Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.55 (PTR)
 433 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The formation of acrylamide was measured in real time during thermal treatment (120-170 degrees C) of potato as well as in Maillard model systems composed of asparagine and reducing sugars, such as fructose and glucose. This was achieved by on-line monitoring of acrylamide released into the headspace of the samples using proton transfer reaction mass spectrometry (PTR-MS). Unambiguous identification of acrylamide by PTR-MS was accomplished by gas chromatography coupled simultaneously to electron-impact MS and PTR-MS. The PTR-MS ion signal at m/z 72 was shown to be exclusively due to protonated acrylamide obtained without fragmentation. In model Maillard systems, the formation of acrylamide from asparagine was favored with increasing temperature and preferably in the presence of fructose. Maximum signal intensities in the headspace were obtained after approximately 2 min at 170 degrees C, whereas 6-7 min was required at 150 degrees C. Similarly, the level of acrylamide released into the headspace during thermal treatment of potato was positively correlated to temperature.
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PMID:Proton transfer reaction mass spectrometry, a tool for on-line monitoring of acrylamide formation in the headspace of maillard reaction systems and processed food. 1471 Aug 29

The PTR 2 gene of Saccharomyces cerevisiae encodes a major peptide permease responsible for the uptake of low-molecular-weight peptides consisting of two or three amino acids. We show that the PTR 2 gene of sake yeast encodes a major peptide permease in the main mash of sake brewing. The peptide uptake activity in sake yeast is decreased by the addition of certain types of amino acids, particularly asparagine, serine and lysine. Northern blot analysis suggested that asparagine and serine repress the expression of the PTR 2 gene, but lysine decreases the peptide transport activity without repressing PTR 2 gene transcription. The deletion analysis of the PTR 2 promoter region confirmed these suggestions and revealed that the cis-element involved in the regulation of the PTR 2 gene by amino acids is located in the region from residue --400 to the start codon.
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PMID:Effect of amino acids on peptide transport in sake yeast. 1623 6