Description

• General description: Elastase is a single polypeptide chain of 240 amino acid residues and contains four disulfide bridges.[1] The molecular mass is approximately 25.9 kDa. The enzyme is synthesized as an inactive zymogen, proelastase,[2] which is converted to the active form by limited proteolysis at the N-terminal by trypsin.
• Application: Elastase from Sigma has been used to examine the extent of proteolytic degradation of BSA that is treated with hydroxyl radical.[3] It has also been used to purify elastase-inhibitory lipid derivative from a cyanobacterium, Microcystis Ku2.[4]
• Biochem/physiol Actions: Elastase is a serine protease with broad specificity as it cleaves protein at the carboxyl side of small hydrophobic amino acids such as Ile, Gly, Ala, Ser, Val and Leu.[9] The enzyme also hydrolyzes amides and esters such as N-Benzoyl-L-alanine methyl ester. The pH optimum is found to be 8.0-8.5. It does not require any activator, but it is inhibited by diisopropyl fluorophosphate, phenylmethanesulfonyl fluoride, α2-macroglobulin, α1-antitrypsin, sulfonyl fluorides and p-dinitrophenyl diethylphosphate and high salt concentrations. It is extensively used in tissue and cell dissociation procedures. Elastase is effective in the isolation of Type II lung cells. Elastase hydrolyses elastin, the specific protein of elastic fibers, and digests hemoglobin, casein and fibrin.[10]
• Packaging: Package size based on protein content
• Unit Definition: One unit will hydrolyze 1.0 μmole of N-succinyl-L-Ala-Ala-Ala-p-nitroanilide per min, pH 8.0 at 25 °C.
• Physical form: Contains sodium carbonate.
• Preparation Note: A further purification of Type III, E 0127, by affinity chromatography to reduce trypsin activity