At the request of a commenter over at Pharyngula, I’m looking at the abstract of a paper on what’s in the cells of normal skin vs. skin in an outbreak of psoriasis, a scaly, itchy, and persistent skin condition. This is mostly just for translation into simpler English.
The paper is Subcellular distribution of phosphatases, proteinases, and ribonucleases in normal human stratum corneum and psoriatic scales. The authors are F. Jochen Förster, Anita Neufahrt, Gerhard Stockum, Kurt Bauer, Sabine Frenkel, Ute Fertig and Gottfried Leonhardi—all from Abteilung IV (Biochemie) im Zentrum, Dermatologie und Venerologie Universität Frankfurt, FRG.
Journal: Archives of Dermatological Research
Issue: Volume 254, Number 1 / January, 1975
Publisher: Springer, Berlin / Heidelberg
ISSN : 0340-3696 (Print) 1432-069X (Online)
Summary: The subcellular distribution of phosphatases, proteinases, and ribonucleases of normal human stratum corneum and psoriatic scales was determined after differential centrifugation. All psoriatic enzymes showed much increased activities as compared to the normal stratum corneum enzymes. The highest activities of alkaline phosphatase from psoriatic scales could be detected in the nuclear fraction. The main activities of all other tested phosphatases and proteinases were present in the cytoplasmatic fraction. The subcellular distribution of the ribonucleases varied according to the pH value.
Zusammenfassung: Nach fraktionierter Zentrifugation wurde die subcelluläre Verteilung von Phosphatasen, Proteinasen und Ribonukleasen aus normalem menschlichem Stratum corneum und Psoriasisschuppen bestimmt. Alle Enzyme aus Psoriasisschuppen zeigten wesentlich mehr Aktivität als die entsprechenden Enzyme aus normalem Stratum corneum. Die stärkste Aktivität der alkalischen Phosphatase aus Psoriasisschuppen wurde in der Kernfraktion gemessen. Die stärkste Aktivität der übrigen Phosphatasen und der Proteinasen wurde in der cytoplasmatischen Fraktion gefunden. Die subcelluläre Verteilung der Ribonukleasen veränderte sich entsprechend dem pH-Wert.
Here’s my explanation:
They looked at subcellular distribution: where something resides within the cell.
They considered these enzymes:
- Phosphatase: any enzyme that removes a phosphate group from a molecule
- Proteinase (also called protease): any enzyme that breaks a link between two amino acids. It does so by adding a water molecule to a peptide bond; therefore the process is also called hydrolysis (water-digesting).
- Ribonuclease (also called RNase): any enzyme that splits ribonucleic acid strands, also by hydrolysis. They are very common and break down any loose RNA in the cell.
They compared cells from a normal outer layer of skin and those from areas of the skin with psoriasis. The outer layer of the epidermis is called the stratum corneum or horny layer because the skin cells are tough keratin to protect the layers below.
They separated the cell components. I think it was only into the nucleus and cytoplasm (cell goo, the rest of the cell).
The psoriatic cells contained higher amounts of all the enzymes. In those cells, the highest amounts of alkaline phosphatases were in the nucleus. Everything else was higher in the cytoplasm.
The location of ribonucleases varied with the acidity of the environment (within the cell, I guess).
At that point my knowledge runs out. I don’t know what alkaline phosphatases do in particular. And I’d have to pay to see the whole paper, even though it’s from 1975.
Dr. Leonhardi did work with the urine compounds produced by patients with melanoma in the 1950s: MELANOGENURIA : THE PAST – THE PRESENT – THE FUTURE.
Dr. Leonhardi has very little presence on the Web. I think that he retired long before everyone had their CVs online.