Display options
Cite
Quail PH, Browning A. Failure of lactoperoxidase to iodinate specifically the plasma membrane of cucurbita tissue segments. Plant Physiol. 1977;59(4):759-66doi: 10.1104/pp.59.4.759.
Quail, P. H., & Browning, A. (1977). Failure of lactoperoxidase to iodinate specifically the plasma membrane of cucurbita tissue segments. Plant physiology, 59(4), 759-66. https://doi.org/10.1104/pp.59.4.759
Quail, P H, and Browning, A. "Failure of lactoperoxidase to iodinate specifically the plasma membrane of cucurbita tissue segments." Plant physiology vol. 59,4 (1977): 759-66. doi: https://doi.org/10.1104/pp.59.4.759
Quail PH, Browning A. Failure of lactoperoxidase to iodinate specifically the plasma membrane of cucurbita tissue segments. Plant Physiol. 1977 Apr;59(4):759-66. doi: 10.1104/pp.59.4.759. PMID: 16659933; PMCID: PMC542488.
Copy Download .nbib Format: NLM
Share it on

Plant Physiol. 1977 Apr;59(4):759-66. doi: 10.1104/pp.59.4.759.

Failure of lactoperoxidase to iodinate specifically the plasma membrane of cucurbita tissue segments.

Plant physiology

P H Quail, A Browning

Affiliations

  1. Research School of Biological Sciences, Australian National University, Canberra, A.C.T. 2601, Australia.

PMID: 16659933 PMCID: PMC542488 DOI: 10.1104/pp.59.4.759

Abstract

An attempt has been made to use lactoperoxidase-catalyzed iodination of excised Cucurbita hypocotyl hooks to monitor the distribution of plasma membrane fragments relative to that of phytochrome in particulate fractions from this tissue. Upon fractionation, the iodinated tissue yields a 20,000g pellet which contains 58% of the trichloroacetic acid-precipitable (125)I at a specific radioactivity 12 times that of the proteins in the supernatant. On sucrose gradients, the labeled fraction has a mean isopycnic density of 1.15 g . cm(-3). The distribution profile is distinct from that of the total particulate protein and does not coincide with either mitochondrial or endoplasmic reticulum markers. These observations satisfy operational criteria commonly accepted in other systems as indices of selective labeling of the cell surface. The sucrose gradient profiles of the phytochrome and (125)I in the 20,000g pellets are noncoincident. In the absence of more direct evidence, this is readily interpreted to indicate a lack of association of the pigment with the plasma membrane.Autoradiographic analysis indicates, however, that the (125)I is almost exclusively associated with an amorphous film (possibly phloem-exudate protein) overlying the cut cells at the point of prelabeling excision and along the outer physical surface of the hypocotyl cuticle. No evidence of plasma membrane labeling is apparent. The observed membrane-like behavior of the iodinated material upon cell fractionation is attributed to the preferential posthomogenization association of this material with a particular membrane fraction(s). These data indicate that in addition to the well recognized potential for spurious labeling of the internal cytoplasmic proteins of leaky cells, a further source of ambiguity in surface-labeling experiments should be considered. That is, the potential for labeling extracellular proteins of nonplasma membrane origin but with a capacity to become associated with membranes upon homogenization.

References

  1. J Cell Biol. 1973 Jun;57(3):659-67 - PubMed
  2. J Cell Biol. 1972 Nov;55(2):390-405 - PubMed
  3. Folia Histochem Cytochem (Krakow). 1975;13(1-2):11-20 - PubMed
  4. Proc Natl Acad Sci U S A. 1972 Nov;69(11):3307-11 - PubMed
  5. Biochem J. 1975 Oct;152(1):71-84 - PubMed
  6. J Ultrastruct Res. 1969 Jan;26(1):31-43 - PubMed
  7. Biochim Biophys Acta. 1975 Dec 29;415(4):379-410 - PubMed
  8. J Biol Chem. 1951 Nov;193(1):265-75 - PubMed
  9. Methods Enzymol. 1974;32:103-9 - PubMed
  10. Proc Natl Acad Sci U S A. 1974 Apr;71(4):1413-7 - PubMed
  11. Biochim Biophys Acta. 1975 Jan 28;375(2):249-67 - PubMed
  12. Plant Physiol. 1974 Sep;54(3):333-40 - PubMed

Publication Types