The obligation to make annuity payments to individuals under charitable gift annuity agreements issued by the board of a state university, regional university, or of the state college pursuant to RCW
28B.10.485 shall be secured by and limited to the assets given in exchange for the annuity and reserves established by the board. Such agreements shall not constitute:
(1) An obligation, either general or special, of the state; or
(2) A general obligation of a state university, regional university, or of the state college or of the board.