How to use getters and setters in PHP domain objects and transfer them correctly with Zend_Amf

Question

I just started to use Zend_Amf and thus far I'm really happy with it for sending objects from Flash to the server. Sending my objects from the server back to my Flash environment is causing me a slight headache. My PHP objects mostly contain private properties that have a custom getter and setter method. How do I make Zend_Amf aware of these properties? When sending objects from the server back to PHP it just tries. Is there an annotation for this like @property? Any help is much appreciated, for now I'll try to convert the object to an stdClass instance with a $_ecplicitType value.