How to (de)serialise JSON data in Silverlight using a different name to member variable

[DataMemberAttribute(Name = "cust_title")]
    	public String Title { get; set; }
    	[DataMemberAttribute(Name = "cust_description")]
    	public String Description { get; set; }

[DataContractAttribute]
public class MyClass
{
  [DataMemberAttribute(Name="test_test")]
  public String Test { get; set; }
}