var myClass = function(json){
    var self = this;

    self.myMethod = function(){
    	console.log("Calling my method")
    };

    for(var key in json){
        if(typeof json[key] === "object"){
            self[key] = new myClass(self[key]);
        } else {
            self[key] = json[key];
        }
    }
};

var jsonObject = {a:"1", b:{b1:"2"}};

// All objects and sub-objects have myMethod()
var classedJson = new myClass(jsonObject);