c# XmlSerialization collapse class to give particular value

Question

I'm working on some classes in c#. They need to be serialized to XML to match an existing schema, but I want to build the validation in the code. e.g. something like the below;

public class Address {
        public AddressLineType AddressLine1 {get;set;}
        public AddressLineType AddressLine2 {get;set;}
        public ShortAddressLineType AddressTown {get;set;}
        public ShortAddressLineType AddressCounty {get;set;}
        public PostCodeType PostCode {get;set;}
    }

    public class SimpleString {
        public string Value {get;set;}
        public override string ToString() {
            return Value;
        }
    }

    public class AddressLineType : SimpleString {
        static readonly int maxLength = 60;
        public static explicit operator AddressLineType(string v) {
            if(!(v.Length < maxLength)) throw new Exception("String is to long!");
            AddressLineType s = new AddressLineType();
            s.Value = v;
            return s;
        }
    }

    public class ShortAddressLineType : SimpleString {
        static readonly int maxLength = 30;
        public static explicit operator ShortAddressLineType(string v) {
            if(!(v.Length < maxLength)) throw new Exception("String is to long!");
            ShortAddressLineType s = new ShortAddressLineType();
            s.Value = v;
            return s;
        }
    }

    public class PostCodeType : SimpleString {
        public static explicit operator PostCodeType(string v) {
        Regex regex = new Regex(""); //PostCode pattern..
            if(!(regex.IsMatch(v))) throw new Exception("Regex Validation Failed.");
            PostCodeType s = new PostCodeType();
            s.Value = v;
            return s;
        }
    }

However, when this is serialized the result is;

<CurrentAddress>
 <AddressLine1>
  <Value>3 The Street</Value>
 </AddressLine1>
 <AddressLine2>
  <Value>Foo Town</Value>
 </AddressLine2>
</CurrentAddress>

Is it possible to collapse the special classes so that the result is this instead, but still be able to do validation? e.g. I need to specify that the AddressLineType serialises to it's Value only.

<CurrentAddress>
 <AddressLine1>3 The Street</AddressLine1>
 <AddressLine2>Foo Town</AddressLine2>
</CurrentAddress>

This code prints the result;

Address address = new Address();
address.AddressLine1 = (AddressLineType) "3 The Street";
address.AddressLine2 = (AddressLineType) "Foo Town";

XmlSerializer serializer = new XmlSerializer(typeof(Address));
serializer.Serialize(Console.Out, address);