Enzyme changes in lichen planus.

A Jarrett; K M Witham; J A Hardy

doi:10.1007/bf00560365

Home/Archive/PubMed

PubMed · 126044

Enzyme changes in lichen planus.

A Jarrett·K M Witham·J A Hardy

View original source ↗Export metadata ↓

Abstract

Untreated cases of lichen planus have been studied by histochemical techniques. The acid phosphatase reaction in the transitional zone has been quantitatively estimated and compared with the adjacent relatively normal epidermis. It was found that despite a thickened and accentuated granular layer as seen by routine histological methods there was a marked reduction in the intensity of the acid phosphatase reaction. The glucose-6-phosphate dehydrogenase reaction was marked in the upper layers of the epidermis in active lesions of lichen planus. This is similar to psoriasis, but different from normal human epidermis. The suggestion by other authors that lichen planus is an inborn error of metabolism is discussed. The dendritic cells of the epidermis as studied by the ATPase reaction are virtually absent in regions of active lichen planus and the possible significance of this is mentioned. The horny layer gives a dense reaction for phospholipids in lichen planus and this is similar to psoriatic keratin. The significance of this finding is considered.

Explore related subjects

Acid Phosphatase Adenosine Triphosphatases Dendrites Glucosephosphate Dehydrogenase Histocytochemistry Humans Keratins Lichen Planus Metabolism, Inborn Errors Naphthols Phospholipids Skin Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

A Jarrett, K M Witham, J A Hardy. 1975-07-18. Enzyme changes in lichen planus.. https://doi.org/10.1007/bf00560365

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

Analysis of the ACP1 gene product: classification as an FMN phosphatase.

The relationship between the ACP1 gene product, an 18kDa acid phosphatase (E.C. 3.1.3.2) postulated to function as a protein tyrosyl phosphatase, and the cellular flavin mononucleotide (FMN) phosphatase has been examined in vitro and by using cultured Chinese hamster ovary (CHO) cells. Kinetic analysis indicated that at pH 6 the acid phosphatase utilized a variety of phosphate monoesters as substrates. While small molecules such as FMN were effectively utilized as substrates (kcat/Km = 7.3 x 10(3) s-1M-1), the tyrosyl phosphorylated form of the adipocyte lipid binding protein was a relatively poor substrate (kcat/Km = 1.7 x 10(-1) s-1M-1) suggesting a role for the phosphatase in flavin metabolism. Fractionation of CHO cell extracts revealed that 90% of the FMN phosphatase activity was soluble and that all of the soluble activity eluted from a Sephadex G-75 column with the acid phosphatase. All of the soluble FMN phosphatase activity was inhibited by immunospecific antibodies directed against the bovine heart ACP1 gene product. These results suggest that the ACP1 gene product functions cellularly not as a protein tyrosyl phosphatase but as a soluble FMN phosphatase.

Acid Phosphatase↗

PubMed1992

Interaction of porcine uterine fluid purple acid phosphatase with vanadate and vanadyl cation.

Uteroferrin, the purple acid phosphatase from porcine uterine fluid, is noncompetitively inhibited by vanadate in a time-dependent manner under both aerobic and anaerobic conditions. This time-dependent inhibition is observed only with the diiron enzyme and is absent when the FeZn enzyme is used. The observations are attributed to the sequential formation of two uteroferrin-vanadium complexes. The first complex forms rapidly and reversibly, while the second complex forms slowly and results in the production of catalytically inactive oxidized uteroferrin and V(IV), which is observed by EPR. The redox reaction can be reversed by treatment of the oxidized enzyme first with (V(IV)) and then EDTA to generate a catalytically active uteroferrin. Multiple inhibition kinetics suggests that vanadate is mutually exclusive with molybdate, tungstate, and vanadyl cation. The binding site for each of these anions is distinct from the site to which the competitive inhibitors phosphate and arsenate bind. The time-dependent inhibition by vanadate of uteroferrin containing the diiron core represents a new type of mechanism by which vanadium can interact with proteins and gives additional insight into the binding of anions to uteroferrin.

Acid Phosphatase↗

PubMed1992

Nucleosome disruption at the yeast PHO5 promoter upon PHO5 induction occurs in the absence of DNA replication.

Activation of the PHO5 gene in S. cerevisiae by phosphate starvation was previously shown to be accompanied by the disappearance of four positioned nucleosomes from the promoter. To investigate the mechanism, we replaced the PHO80 gene, a negative regulator of PHO5, by a temperature-sensitive allele. As a consequence, PHO5 can be activated in the presence of phosphate by a temperature shift from 24 degrees C to 37 degrees C. Under these conditions, the promoter undergoes the same chromatin transition as in phosphate-starved cells. Disruption of the nucleosomes by the temperature shift also occurs when DNA replication is prevented. Nucleosomes re-form when the temperature is shifted from 37 degrees C back to 24 degrees C in nondividing cells. Glucose is required for the disruption of the nucleosomes during the temperature upshift, not for their re-formation during the temperature downshift. These experiments prove that DNA replication is not required for the transition between the nucleosomal and the non-nucleosomal state at the PHO5 promoter.

Acid Phosphatase↗