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Actomyosin content of Physarum plasmodia and detection of immunological cross-reactions with myosins from related species

The content of myosin in plasmodia of the myxomycete Physarum polycephalum was measured by an immunological technique, quantitative microcomplement (C') fixation. Migrating plasmodia (starved after growth on rolled oats) contained 0.60 +/- 0.08 (SD) mg myosin per g fresh plasmodia. Myosin compr...

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Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1976
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Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2109671/
https://www.ncbi.nlm.nih.gov/pubmed/944188
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description The content of myosin in plasmodia of the myxomycete Physarum polycephalum was measured by an immunological technique, quantitative microcomplement (C') fixation. Migrating plasmodia (starved after growth on rolled oats) contained 0.60 +/- 0.08 (SD) mg myosin per g fresh plasmodia. Myosin comprised 0.77% +/- 0.05 (SD) of the total plasmodial protein. When total plasmodial proteins were separated by electrophoresis on SDS-polyacrylamide gels, a large amount of protein appeared in a band comigrating with muscle actin. Densitometry performed after Coomassie blue staining indicated that as much as 15- 25% of the total protein in the plasmodium could be actin. This gives an actin/myosin ratio by weight in the myxomycete plasmodium as high as 19-33, a very "actin-rich" actomyosin compared with rabbit skeletal muscle actomyosin with an actin/myosin ratio of 0.6. Starvation stimulates rapid migration and is correlated with a higher percent of both myosin and actin in the total protein of the plasmodium compared with normally growing cultures. Immunological cross-reaction of myosins from a variety of species was measured by C' fixation using an antiserum produced against purified native myosin from P. polycephalum. Although myxomycete and vertebrate striated muscle myosins have very similar morphological and biochemical properties, and apparently possess similar binding properties to F-actin, only myosins from myxomycetes in the order Physarales, rather closely related to P. polycephalum, gave detectable cross-reactions. This finding suggests that many amino acid sequences in myosin have been variable during evolution.
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spelling pubmed-21096712008-05-01 Actomyosin content of Physarum plasmodia and detection of immunological cross-reactions with myosins from related species J Cell Biol Articles The content of myosin in plasmodia of the myxomycete Physarum polycephalum was measured by an immunological technique, quantitative microcomplement (C') fixation. Migrating plasmodia (starved after growth on rolled oats) contained 0.60 +/- 0.08 (SD) mg myosin per g fresh plasmodia. Myosin comprised 0.77% +/- 0.05 (SD) of the total plasmodial protein. When total plasmodial proteins were separated by electrophoresis on SDS-polyacrylamide gels, a large amount of protein appeared in a band comigrating with muscle actin. Densitometry performed after Coomassie blue staining indicated that as much as 15- 25% of the total protein in the plasmodium could be actin. This gives an actin/myosin ratio by weight in the myxomycete plasmodium as high as 19-33, a very "actin-rich" actomyosin compared with rabbit skeletal muscle actomyosin with an actin/myosin ratio of 0.6. Starvation stimulates rapid migration and is correlated with a higher percent of both myosin and actin in the total protein of the plasmodium compared with normally growing cultures. Immunological cross-reaction of myosins from a variety of species was measured by C' fixation using an antiserum produced against purified native myosin from P. polycephalum. Although myxomycete and vertebrate striated muscle myosins have very similar morphological and biochemical properties, and apparently possess similar binding properties to F-actin, only myosins from myxomycetes in the order Physarales, rather closely related to P. polycephalum, gave detectable cross-reactions. This finding suggests that many amino acid sequences in myosin have been variable during evolution. The Rockefeller University Press 1976-05-01 /pmc/articles/PMC2109671/ /pubmed/944188 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Actomyosin content of Physarum plasmodia and detection of immunological cross-reactions with myosins from related species
title Actomyosin content of Physarum plasmodia and detection of immunological cross-reactions with myosins from related species
title_full Actomyosin content of Physarum plasmodia and detection of immunological cross-reactions with myosins from related species
title_fullStr Actomyosin content of Physarum plasmodia and detection of immunological cross-reactions with myosins from related species
title_full_unstemmed Actomyosin content of Physarum plasmodia and detection of immunological cross-reactions with myosins from related species
title_short Actomyosin content of Physarum plasmodia and detection of immunological cross-reactions with myosins from related species
title_sort actomyosin content of physarum plasmodia and detection of immunological cross-reactions with myosins from related species
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2109671/
https://www.ncbi.nlm.nih.gov/pubmed/944188