Isolation and partial characterization of a murine cell surface glycoprotein with affinity for exogenously added beta 2-microglubulin.

Exogenously added beta 2-microglobulin (beta 2m) binds to a variety of murine cell types. The 'receptor' for beta 2m has been isolated. The purified 'receptor' comprised a 48,000-dalton chain and occasionally a 25,000-dalton component. Direct crosslinking of beta 2m to the receptor on intact cells gave rise to a single 60,000-dalton beta 2m-'receptor' complex. The molecular characteristics of the 'receptor' were considerably changed on binding beta 2m. The size of the beta 2m-'receptor' complex was increased partly due to enhanced binding of deoxycholate. The 'receptor' was less easily degraded by proteases when beta 2m was bound then when free. The solubilized 'receptor' reacted with a heteroantiserum raised against H-2K and D antigens but did not exhibit any alloantigenic determinants shared with H-2K, D or Ia antigens.