QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Coughlin, M. D. Articles by Jung, C. Y. Search for Related Content PubMed PubMed Citation Articles by Coughlin, M. D. Articles by Jung, C. Y.

 Previous Article  |  Next Article 

Journal of Neuroscience, Vol 6, 1553-1559, Copyright © 1986 by Society for Neuroscience

ARTICLE

Determination of the molecular weight of neuronectin, a conditioned medium-derived, substrate-binding neurite-extension factor: comparison with laminin using radiation-inactivation analysis

MD Coughlin, AK Grover and CY Jung

Neurite outgrowth from a wide variety of peripheral neurons is stimulated and may be directed in culture by a substrate-binding factor(s) derived from medium conditioned over numerous types of cells. This factor, or family of factors, which we shall call neuronectin by reason of its ability to serve as an attachment molecule for neurons, has been studied by target-size analysis using radiation inactivation. The radiation-inactivation method has the unique advantage of providing a means for determining the actual functional size of a biologically active molecule irrespective of its state of purification. By this method, the functional size of the major neurite outgrowth-promoting activity (neuronectin) from mouse heart cell conditioned medium has been found to be 350,000 Da. While neuronectin has not yet been purified, determination of the actual functional size provides a framework within which possible models must fit. Thus, although neurite outgrowth-promoting activity in this system is found to be associated with a complex containing laminin, fibronectin, heparan sulfate proteoglycan, and other extracellular matrix molecules, the total size of the functional molecule or molecular complex serving as the major source of activity is limited to 350,000 Da. Consequently, our results suggest that neuronectin from mouse heart cell-conditioned medium is different from laminin (Mr approximately 900,000), a molecule that also exhibits neurite-promoting activity. In addition to the difference in molecular size, neuronectin and laminin differ in that laminin, unlike neuronectin, gives rise to toxic or inhibitory products when exposed to high-energy radiation.

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help