If you go to your favorite search engine and type in
extensis portfolio to lightroom
you will find some discussion on this topic
Raw files, or just TIF/PSD/JPEG ? If the latter, in Portfolio you can embed the metadata in the files. For raw files, my Portfolio experience is a bit hazy now, and I'm not sure if 8.5 can create xmp files. Do you know? If so, that would be the ideal route. If not, I recall you can export metadata as a text file and use a LR plugin such as LrTransporter to bring the data into LR.
I have a raw/Jpeg/Tif and PSDs, but the majority of my files are Raw.
I'm not sure if Portfolio can create XMPs, I'll check into that.