PMID: 42385Sep 1, 1979

Isolation and partial characterization of three acidic proteinases in erythrocyte membranes

The Biochemical Journal
S PontremoliA De Flora


1. The distribution of proteolytic activity in membranes from human erythrocytes and from rabbit reticulocytes and erythrocytes was investigated, after removal of leucocytes and platelets from the cell suspensions. 2. All membrane preparations displayed proteolytic activity in the acidic pH region only. Membranes from human and rabbit mature erythrocytes showed latent activity, which could be increased when extracted with a number of detergents. 3. Three active fractions were resolved either by gel chromatography of solubilized membrane extracts or by standard polyacrylamide-gel electrophoresis. The three proteinase activities (designated proteinases I, II and III) were purified from solubilized extracts of human erythrocyte membranes. 4. The relevant mol.wts. were around 80000, 40000 and 30000, respectively, and each of the three proteinases appeared to be composed of a single polypeptide chain. 5. Distinctive pH optima (in the range pH2.8-3.9) and different saturation profiles with globin as substrate were observed for proteinases I, II and III. 6. Dithioerythritol, Hg(2+) and Cu(2+) inhibited each of the three human enzymes, but more selective inhibitory effects were exerted by other modifiers of proteolytic enzymes and by h...Continue Reading


Jul 1, 1988·Toxicology and Applied Pharmacology·M A Runge-MorrisR F Novak
Aug 1, 1981·British Journal of Haematology·V Bocci
Jan 1, 1986·Journal of Free Radicals in Biology & Medicine·K J Davies
Oct 15, 1982·Archives of Biochemistry and Biophysics·E MelloniS Pontremoli
Jan 1, 1982·European Journal of Biochemistry·A M Golovtchenko-MatsumotoT Osawa
Jun 1, 1981·Biochemical and Biophysical Research Communications·D A Schafer, D E Hultquist
Jun 1, 1988·Biochemical Medicine and Metabolic Biology·K K Gambhir, S G Nerurkar
Jun 1, 1985·Archives of Biochemistry and Biophysics·U BenattiA De Flora
Sep 1, 1980·European Journal of Biochemistry·S PontremoliA De Flora
Aug 1, 1980·European Journal of Biochemistry·M MüllerS Rapoport

Related Concepts

Cations, Divalent
Tissue Membrane
Mature Erythrocytes
Enzymes, antithrombotic
Peptide Hydrolases
Reticulocyte Count (Procedure)
Proteolytic enzymes for treatment of wounds and ulcers

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Synapse Loss as Therapeutic Target in MS

As we age, the number of synapses present in the human brain starts to decline, but in neurodegenerative diseases this occurs at an accelerated rate. In MS, it has been shown that there is a reduction in synaptic density, which presents a potential target for treatment. Here is the latest research on synapse loss as a therapeutic target in MS.

Artificial Intelligence in Cardiac Imaging

Artificial intelligence (ai) techniques are increasingly applied to cardiovascular (cv) medicine in cardiac imaging analysis. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

Social Learning

Social learning involves learning new behaviors through observation, imitation and modeling. Follow this feed to stay up to date on the latest research.

Cell Atlas of the Human Eye

Constructing a cell atlas of the human eye will require transcriptomic and histologic analysis over the lifespan. This understanding will aid in the study of development and disease. Find the latest research pertaining to the Cell Atlas of the Human Eye here.

Single Cell Chromatin Profiling

Techniques like ATAC-seq and CUT&Tag have the potential to allow single cell profiling of chromatin accessibility, histones, and TFs. This will provide novel insight into cellular heterogeneity and cell states. Discover the latest research on single cell chromatin profiling here.

Genetic Screens in iPSC-derived Brain Cells

Genetic screening is a critical tool that can be employed to define and understand gene function and interaction. This feed focuses on genetic screens conducted using induced pluripotent stem cell (iPSC)-derived brain cells.