Option selected by translation or/and key

Part of my pug file looks like that:

select.form-control(name="street_prefix" id="street_prefix" ng-model="$ctrl.accepterForm.address.streetPrefix" ng-options="prefix.key as prefix.translation for prefix in $ctrl.streetPrefixes")

When i pass json object to page that contains:

streetPrefix:"Ul."

the option is not selected. Additionaily the streetPrefix gets STREET value after the form is submitted as it stands in dictionairy:

key:"STREET" translation:"Ul."

I want that the option Ul. to be selected and aditionaily the same when i get json with streetPrefix:"STREET"

More over i would like to know how can i change value from STREET to .Ul when form is submitted.

Angular 1.6

Edit

tried

 ng-options="prefix.translation as prefix.translation for prefix in $ctrl.streetPrefixes track by prefix.translation")

sends Ul. on submit, but when json has streetPrefix:"Ul." still does not select it as value