GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-2145
    Keywords: Cell adhesion ; Cell-cell recognition ; Chlamydomonas eugametos ; Chlamydomonas moewusii ; Sexual agglutinins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mt− agglutinins of the interfertile species Chlamydomonas moewusii and Chlamydomonas eugametos are very similar fibrous molecules. The mt− agglutinin of C. moewusii has the same Stokes radius (39 nm) and sedimentation coefficient (9.3 S) as its counterpart in C. eugametos; its length (336 nm) and its ultrastructure, including the position of four kinks are also the same as in C. eugametos. The sugar compositions of both agglutinins are very similar, and they react equally well with the monoclonal antibody Mab 66.3 raised against the mt− agglutinin of C. eugametos. Finally, they are equally thermoresistant, with half-lives at 100 °C of 50 min (C. moewusii) and 57 min (C. eugametos). The mt+ agglutinins of both species are different. Both are fibrous molecules with a terminal head, but the fibrous part of the molecule in C. moewusii is shorter (210 nm compared to 276 nm). The mt+ agglutinin of C. moewusii is also significantly more sensitive to heating with a half-life of 6 min at 40 °C compared to the 20 min shown by the mt+ agglutinin of C. eugametos. Their sugar compositions are, however, very similar, and they react equally well with Mab 66.3. The mt+ agglutinin of C. moewusii is sensitive to denaturing reagents and proteolytic attack, whereas the mt− agglutinin is highly resistant. It is proposed that the globular head of the mt+ agglutinin acts as its recognition domain and interacts with a carbohydrate ligand on the mt− agglutinin.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2048
    Keywords: Agglutinin ; Cell-cell recognition ; Chlamydomonas ; Hydroxyproline-rich glycoprotein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sexual interaction between gametes of opposite mating type (mt) of the unicellular green alga Chlamydomonas eugametos starts with agglutination of the cells via particular glycoproteins on the flagellar surface. Purification of these socalled agglutinins was achieved by a three-step procedure consisting of, successively, gel filtration, anion-exchange chromatography, and high-performance gel filtration. The amino-acid and sugar compositions of both agglutinins showed a high degree of similarity; the most prominent amino acids were hydroxyproline, serine and glycine, and the main sugars were arabinose and galactose. The carbohydrate portions represented about half of the molecular mass of both agglutinins. Using high-performance gel filtration, a calibration curve was constructed for high-molecular-mass compounds from which the Stokes' radius of the sexual agglutinins could be estimated. The mt + agglutinin had a Stokes' radius of 39 nm and a sedimentation coefficient of 9.3 S. From these data its molecular mass was estimated to be 1.2·106. The corresponding data for the mt - agglutinin were 38 nm, 9.7 S and 1.3·106, respectively. The biological activity of both agglutinins was destroyed by mild periodate treatment. Treatment with specific glycosidases had a differential effect on the biological activity of the agglutinins. These observations indicate that carbohydrate side-chains are needed for biological activity and perhaps are responsible for the specifity of the sexual agglutinins. A comparison of both agglutinins is given and their possible structure is discussed in relation to their amino-acid and sugar compositions.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...