Abstract
The subunit protein has been isolated from the central-pair and outer-doublet microtubules of sea urchin sperm tails. Both proteins have a sedimentation constant of 6S and a molecular weight of 120,000. Both are converted to a 60,000 molecular weight species by denaturation in 6 M guanidine hydrochloride and reduction with mercaptoethanol. The reduced-alkylated proteins have the same Rf on disc electrophoresis, and the same amino acid composition, which is very similar to that of muscle actin. The central-pair protein has one binding site for colchicine per 120,000 g. Both proteins appear to have a guanine nucleotide binding site, but the ability to bind GTP in solution has been demonstrated only for the central-pair protein. Although 1 mole of guanine nucleotide is bound per 60,000 g to outer-doublet tubules, the protein obtained by dissolving the doublets at pH 10.5 has lost the guanine nucleotide-binding site and also shows little or no colchicine-binding activity. Comparison of the properties of the isolated protein with electron microscopic evidence on structure of microtubules suggests that the chemical subunit (M = 120,000) consists of two of the 40 A morphological subunits.
Full Text
The Full Text of this article is available as a PDF (758.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Andrews P. Estimation of the molecular weights of proteins by Sephadex gel-filtration. Biochem J. 1964 May;91(2):222–233. doi: 10.1042/bj0910222. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Borisy G. G., Taylor E. W. The mechanism of action of colchicine. Binding of colchincine-3H to cellular protein. J Cell Biol. 1967 Aug;34(2):525–533. doi: 10.1083/jcb.34.2.525. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Borisy G. G., Taylor E. W. The mechanism of action of colchicine. Colchicine binding to sea urchin eggs and the mitotic apparatus. J Cell Biol. 1967 Aug;34(2):535–548. doi: 10.1083/jcb.34.2.535. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ELLMAN G. L. Tissue sulfhydryl groups. Arch Biochem Biophys. 1959 May;82(1):70–77. doi: 10.1016/0003-9861(59)90090-6. [DOI] [PubMed] [Google Scholar]
- Grimstone A. V., Klug A. Observations on the substructure of flagellar fibres. J Cell Sci. 1966 Sep;1(3):351–362. doi: 10.1242/jcs.1.3.351. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- PEASE D. C. THE ULTRASTRUCTURE OF FLAGELLAR FIBRILS. J Cell Biol. 1963 Aug;18:313–326. doi: 10.1083/jcb.18.2.313. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rees M. K., Young M. Studies on the isolation and molecular properties of homogeneous globular actin. Evidence for a single polypeptide chain structure. J Biol Chem. 1967 Oct 10;242(19):4449–4458. [PubMed] [Google Scholar]
- SCANU A., LEWIS L. A., BUMPUS F. M. Separation and characterization of the protein moiety of human alpha1-lipoprotein. Arch Biochem Biophys. 1958 Apr;74(2):390–397. doi: 10.1016/0003-9861(58)90009-2. [DOI] [PubMed] [Google Scholar]
- Shelanski M. L., Taylor E. W. Isolation of a protein subunit from microtubules. J Cell Biol. 1967 Aug;34(2):549–554. doi: 10.1083/jcb.34.2.549. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stephens R. E., Renaud F. L., Gibbons I. R., Stevens R. E. Guanine nucleotide associated with the protein of the outer fibers of flagella and cilia. Science. 1967 Jun 23;156(3782):1606–1608. doi: 10.1126/science.156.3782.1606. [DOI] [PubMed] [Google Scholar]
- YPHANTIS D. A. EQUILIBRIUM ULTRACENTRIFUGATION OF DILUTE SOLUTIONS. Biochemistry. 1964 Mar;3:297–317. doi: 10.1021/bi00891a003. [DOI] [PubMed] [Google Scholar]