Ignore [DataMember(Name = "xx")] at json serialisation

Question

i'm trying to serialize a class which has multiple properties with DataMember attribute. Like this:

[DataMember(Name = "F")]
public string FontFamily { get; set; }

If i serialize my object the name FontFamily was replaced by the name F:

JsonConvert.SerializeObject(obj)

results in

\"F\":\"Arial\"  

How can i force NewtonSoft Json to ignore the DataMember attribute and use the original name?

\"FontFamily\":\"Arial\"  

I have no source code access to change the DataMember attribute.