How to correctly escape or convert special characters in (object)array() when calling __soapCall()?

Question

PHP

"SubjectList" => (object) array (
 "Subject SbjKey=\"1\"" =>  array(
"SbjType" => "New"),									),

$TariffResponce = $client->__soapCall("GetTariff", array($GetTariffRequest));

in response, Uncaught SoapFault exception: [a:InternalServiceFault] Error in deserializing body of request message for operation 'GetTariff'.
without a space or an equals sign, the request passes.