Potential Exposure
These commercial proteolytic enzymes are used in laundry detergent formulations
First aid
If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce vomiting. Do not make an unconscious person vomit.
Incompatibilities
Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.
Chemical Properties
These are proteolytic enzymes which take the form of light-colored, free-flowing powders. A protein containing numerous amino acids
Uses
This is a proteolytic enzyme isolated from the fermentation of Bacillus licheniformis. It is a serine endoproteinase with a broad specificity towards native and denatured proteins, and is active under alkaline conditions. It is for use in Total Dietary Fiber Assays (TDF-100A).
Biosynthesis
Biosynthetically, subtilin is produced from a ribosomally derived pre-pro-peptide by a series of post-translational modifications. [1]
General Description
Proteolytic enzymes are known to possess catalytic, non-catalytic and ancillary domains. Proteases are broadly classified as endopeptidases and exopeptidases. Functionally they are divided as aspartic, glutamic, cysteine, threonine, serine and metalloproteases.
Biochem/physiol Actions
Protease catabolizes proteins by hydrolysis of peptide bonds. Proteases are inactivated by serine active-site inhibitors, such as phenylmethylsulfonyl fluoride (PMSF) and diisopropylfluorophosphate. Proteases, secreted from Bacillus sp., typically have molecular weights ranging from 20,000 to 30,000. They are typcially stabilized by Ca2+ and have high isoelectric points.
Safety Profile
Moderately toxic by ingestion. Aneye irritant. When heated to decomposition it emits toxicfumes of NOx.
Purification Methods
This alkaline protease is purified 211-fold by affinity chromatography using 4-(4-aminophenylazo)phenylarsonic acid complex to activated CH-Sepharose 4B. It is inhibited by 2-phenylethane boronic acid, PMSF, 3,4-dichloroisocoumarin, acetone and benzamide. [Chandraskaren & Dhar Anal Biochem 150 141 1985, Schomburg & Schomburg Springer Handbook of Enzymes 2nd Edn vol 7 p 286 2002.] Synexin (from bovine liver) M 47,000 Da. This Ca binding protein is purified by (NH4)2SO4 precipitation, then by a specific pH step elution from a chromatofocusing medium in the absence of ampholytes. The pI is 7.5. [Scott et al. Anal Biochem 149 163 1985.]
Toxics Screening Level
The initial threshold screening level (ITSL) for subtilisins is 0.0006 μg/m 3 (1-hour averaging time).
References
[1]Burrage, Sarah Anne. Biomimetic synthesis of subtilin. Diss. University of Southampton, 1998
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