Hello Jim,
No, you don't need to enable SPNEGO. You need to configure the User Management Engine (UME) of your AS Java system to read the users and groups from Active Directory. Check the following documentation for details - http://help.sap.com/saphelp_nw74/helpdata/en/12/7678123c96814bada2c8632d825443/frameset.htm.
Regards,
Dimitar