scholarly journals Tropomyosin micelles are the major white components in the boiled soup of shellfish

2021 ◽  
Author(s):  
Ishida Hideki ◽  
Takshi Akihiro ◽  
Ryo Yasui ◽  
Shinji Yasuhira ◽  
Ken-ich Matsumoto ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Trichloroacetic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Laser Desorption ◽  
Peptide Mass Fingerprinting ◽  
Hot Water ◽  
Tandem Mass ◽  
Intense Band ◽  
Peptide Mass

Abstract Basket clam soup, a popular Asian dish, is prepared by boiling clams in hot water. The soup is generally cloudy and considered more delicious as cloudiness increases. However, the identity of the whitening ingredients and their relationship with taste remain unclear. In this study, we aimed to identify the components that contribute to the white color of the boiled soup. The white component was precipitated with trichloroacetic acid and reacted positively with ninhydrin, indicating the presence of proteins. The proteins were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and an intense band was observed at 33 kDa. Peptide mass fingerprinting of this band using matrix-assisted laser desorption/ionisation-time-of-flight tandem mass spectrometry revealed the protein to be tropomyosin. Basket clam tropomyosin expressed and purified from Escherichia coli turned the extracted solution white, confirming that tropomyosin contributed to the white color of clam soup.

scholarly journals Tropomyosin micelles are the major white components in the boiled soup of shellfish

2022 ◽  
Author(s):  
Takashi Akihiro ◽  
Ryou Yasui ◽  
Shinji Yasuhira ◽  
Ken-ich Matsumoto ◽  
Yasuhiro Tanaka ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Trichloroacetic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Laser Desorption ◽  
Peptide Mass Fingerprinting ◽  
Hot Water ◽  
Tandem Mass ◽  
Intense Band ◽  
Peptide Mass

Abstract Basket clam soup, a popular Asian dish, is prepared by boiling clams in hot water. The soup is generally cloudy and considered more delicious as cloudiness increases. However, the identity of the whitening ingredients and their relationship with taste remain unclear. In this study, we aimed to identify the components that contribute to the white color of the boiled soup. The white component was precipitated with trichloroacetic acid and reacted positively with ninhydrin, indicating the presence of proteins. The proteins were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and an intense band was observed at 33 kDa. Peptide mass fingerprinting of this band using matrix-assisted laser desorption/ionisation-time-of-flight tandem mass spectrometry revealed the protein to be tropomyosin. Basket clam tropomyosin expressed and purified from Escherichia coli turned the extracted solution white, confirming that tropomyosin contributed to the white color of clam soup.

scholarly journals Homotaurine Metabolized to 3-Sulfopropanoate in Cupriavidus necator H16: Enzymes and Genes in a Patchwork Pathway

2009 ◽  
Vol 191 (19) ◽  
pp. 6052-6058 ◽  
Author(s):  
Jutta Mayer ◽  
Alasdair M. Cook
Keyword(s):  
Ralstonia Eutropha ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Peptide Mass Fingerprinting ◽  
Sole Source ◽  
Cupriavidus Necator ◽  
Semialdehyde Dehydrogenase ◽  
Peptide Mass ◽  
Cupriavidus Necator H16 ◽  
Sulfoacetaldehyde Acetyltransferase

ABSTRACT Homotaurine (3-aminopropanesulfonate), a natural product and an analogue of GABA (4-aminobutyrate), was found to be a sole source of nitrogen for Cupriavidus necator (Ralstonia eutropha) H16, whose genome sequence is known. Homotaurine nitrogen was assimilated into cell material, and the quantitative fate of the organosulfonate was sulfopropanoate, which was recovered in the growth medium. The first scalar reaction was shown to be inducible homotaurine:2-oxoglutarate aminotransferase, which released 3-sulfopropanal from homotaurine. This aminotransferase was purified to homogeneity and characterized. Peptide mass fingerprinting yielded locus tag H16_B0981, which was annotated gabT, for GABA transaminase (EC 2.6.1.19). Inducible, NAD(P)+-coupled 3-sulfopropanal dehydrogenase, which yielded 3-sulfopropanoate from 3-sulfopropanal, was also purified and characterized. Peptide mass fingerprinting yielded locus tag H16_B0982, which was annotated gabD1, for succinate-semialdehyde dehydrogenase (EC 1.2.1.16). GabT and GabD1 were each induced during growth with GABA, and cotranscription of gabTD was observed. In other organisms, regulator GabC or GabR is encoded contiguous with gabTD: candidate GabR′ was found in strain H16 and in many other organisms. An orthologue of the GABA permease (GabP), established in Escherichia coli, is present at H16_B1890, and it was transcribed constitutively. We presume that GabR′PTD are responsible for the inducible metabolism of homotaurine to intracellular 3-sulfopropanoate. The nature of the exporter of this highly charged compound was unclear until we realized from the sodium dodecyl sulfate-polyacrylamide gel electrophoresis data that sulfoacetaldehyde acetyltransferase (EC 2.3.3.15; H16_B1872) was strongly induced during growth with homotaurine and inferred that the sulfite exporter encoded at the end of the gene cluster (H16_B1874) has a broad substrate range that includes 3-sulfopropanoate.

Products of mitochondrial protein synthesis in Tetrahymena

1979 ◽  
Vol 57 (4) ◽  
pp. 314-320 ◽  
Author(s):  
Paul G. Young ◽  
Neil P. Hunter
Keyword(s):  
Protein Synthesis ◽  
Gel Electrophoresis ◽  
Trichloroacetic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Mitochondrial Protein ◽  
Sodium Dodecyl ◽  
Apparent Molecular Weight ◽  
Mitochondrial Proteins ◽  
Mitochondrial Protein Synthesis ◽  
Chloroform Methanol

The products of mitochondrial protein synthesis have been investigated in Tetrahymena after labelling with [35S]methionine in the presence of cycloheximide. The labelled proteins were analyzed by sodium dodecyl sulfate slab polyacrylamide gel electrophoresis. We have identified 13 electrophoretically discrete bands as well as 4 other bands with a more variable occurrence. These proteins ranged in apparent molecular weight from 8100 to 57 500. The cycloheximide-resistant incorporation could be blocked with chloramphenicol. The mitochondrial proteins appeared to be in a disaggregated state and were stable to agents such as trichloroacetic acid (hot or cold) and chloroform–methanol. The pattern of proteins was similar following labelling times ranging from 30 min to 3 h.

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