NHibernate - use factory instead of constructor

Question

I'm quite new with NHibernate, so I'd like to know if this is possible with NHibernate.

I have a simple type

public class TestInfo
{
    public int Id { get; set; }

    public string SomeProperty1 { get; set; }
    public string SomeProperty2 { get; set; }
    public string SomeProperty3 { get; set; }
}

and I'd like to persist the data in following table

create table tests
(
    [id] int not null primary key,
    [data] varchar(max) not null,
)

and rather then using default constructor for instantiating the object I'd like to use my own function (namely XML Deserialization of data field, to populate the other fields). I tried this by overriding SingleTableEntityPersister.Instantiate method - but here I can only access the id column and not the data column. Is there a way to access all the columns.