<DataGridTemplateColumn Width="0.05*" Header="Активно">
  <DataGridTemplateColumn.CellTemplate>
    <DataTemplate>
      <CheckBox IsChecked="{Binding Path=IsActive, UpdateSourceTrigger=PropertyChanged}"/>
    </DataTemplate>
  </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

public class SiteUserCollection : ObservableCollection<Classes.SiteUser>, INotifyPropertyChanged {
..
}

public class SiteUser : IEquatable<Classes.SiteUser> {
    public bool IsActive {
      get;
      set;
    }
    public string Usercode {
      get;
      set;
    }    
    public string Username {
      get;
      set;
    }
    
    public string Password {
      get;
      set;
    }   

    public bool Equals(SiteUser other) {
      if (Object.ReferenceEquals(other, null))
        return false;
      if (Object.ReferenceEquals(this, other))
        return true;
      return Usercode.Equals(other.Usercode) && Username.Equals(other.Username);
    }


    public override int GetHashCode() {
      ...
    }

  }

              <DataGridTemplateColumn Width="0.15*" Header="Пароль">
                <DataGridTemplateColumn.CellTemplate>
                  <DataTemplate>
                    <PasswordBox Password="{Binding Path=Password, UpdateSourceTrigger=PropertyChanged}"/>                   
                  </DataTemplate>
                </DataGridTemplateColumn.CellTemplate>
              </DataGridTemplateColumn>