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L D McClain

Publications and source records attributed to L D McClain.

10 recordsLinked to original sources
PubMed1978

Purification and characterization of mouse brain Thy-1.2 differentiation alloantigen.

Subcellular fractionation of C57BI/6J mouse brains produced a crude synaptosome preparation which contained virtually all of the Thy-1.2 antigenic activity of the isotonic whole brain homogenate. The Thy-1.2 was solubilized from the synaptosomes, following delipidation with acetone, by deoxycholate extraction. A glycoprotein fraction rich in Thy-1.2 was isolated from the bulk of the detergent-soluble material by lectin affinity chromatography. Fractionation of the lectin retentate by gel filtration chromatography produced a single peak of Thy-1.2 activity purified more than 2000-fold over the original homogenate. SDS polyacrylamide gel electrophoresis of this material revealed a single band which corresponded to an apparent molecular weight of 24,000. Amino acid composition data indicated that the protein portion of the molecule is similar to Thy-1.1 from mouse lymphoblastoid cells. Carbohydrate analysis revealed a qualitative similarity between mouse brain Thy-1.2 and Thy-1.1 from rat brain. Structural differences which could account for the Thy-1.1 and Thy-1.2 antigenic distinctions are apparently too subtle to be detected by compositional analysis.

Amino Acids↗
PubMed1978

Association of Thy-1 differentiation alloantigen with synaptic complexes isolated from mouse brain.

Conventional fractionation procedures were used in an effort to define the subcellular distribution of the Thy-1 alloantigen in whole mouse brain. After discontinuous sucrose density gradient centrifugation of isotonic postnuclear particulate fractions, the bulk of Thy-1 was recovered in regions of the gradients containing synaptosomes. The synaptosome fraction that banded at 1.2 M sucrose yielded a specific activity for Thy-1 significantly greater than the synaptosomes separating at 1.4 M sucrose. Osmotic lysis of both synaptosome fractions resulted in further enrichment in Thy-1 activity, with no concomitant decrease in yields. The synaptosomal membranes obtained in this way were subsequently treated with Triton X-100 and subjected to further density gradient centrifugation. Although the detergent treatment resulted in some loss of antigenic activity, the gradient fractions that contained Thy-1 also were found by electron microscopy to be richest in synaptic junctional complexes. These findings suggest that Thy-1 is associated with synaptosomes and synaptic junctional complexes and therefore may be involved in the formation and/or maintenance of synaptic connections.

Animals↗