You can do it if you define a custom UITypeEditor that overrides the standard CollectionEditor, something like this:

    public class FileInfo
    {
        [DisplayName("Messages")]
        [Editor(typeof(MyCustomCollectionEditor), typeof(UITypeEditor))]
        public Collection<MessageInfo> MessageInfos { get; set; }
    }

    public class MyCustomCollectionEditor : CollectionEditor // needs a reference to System.Design.dll
    {
        public MyCustomCollectionEditor(Type type)
            : base(type)
        {
        }

        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
        {
            if (DontShowForSomeReason(context)) // you need to implement this
                return UITypeEditorEditStyle.None; // disallow edit (hide the small browser button)

            return base.GetEditStyle(context);
        }
    }