scholarly journals Methodological Considerations and Comparisons of Measurement Results for Extracellular Proteolytic Enzyme Activities in Seawater

2017 ◽  
Vol 8 ◽  
Author(s):  
Yumiko Obayashi ◽  
Chui Wei Bong ◽  
Satoru Suzuki
Keyword(s):  
Enzyme Activities ◽  
Proteolytic Enzyme ◽  
Measurement Results ◽  
Extracellular Proteolytic Enzyme ◽  
Methodological Considerations

scholarly journals A PROTEOLYTIC ENZYME PRODUCED BY GROUP A STREPTOCOCCI WITH SPECIAL REFERENCE TO ITS EFFECT ON THE TYPE-SPECIFIC M ANTIGEN

1945 ◽  
Vol 81 (6) ◽  
pp. 573-592 ◽  
Author(s):  
Stuart D. Elliott
Keyword(s):  
Proteolytic Enzyme ◽  
Potassium Cyanide ◽  
Maximal Activity ◽  
Serial Passage ◽  
Iodoacetic Acid ◽  
Broth Culture ◽  
Mouse Serum ◽  
Group A Streptococci ◽  
Extracellular Proteolytic Enzyme ◽  
Group A

1. Group A streptococci sometimes produce in broth culture an extracellular proteolytic enzyme. 2. Under suitable cultural conditions the enzyme has been demonstrated in representative cultures of most of the Griffith types. Its production by a given strain may be suppressed by serial passage through mice and the variant so produced has been found to maintain this change in character on subculture in artificial media. 3. Under certain conditions, the enzyme attacks the type-specific M antigens of all the group A streptococci so far tested, with the exception of that of type 28. The enzyme exhibits its maximal activity at 37°C.: Extracts made from enzyme-producing cultures which have been grown at this temperature lack the M antigen; enzyme-producing strains may sometimes be induced to yield M substance in extracts by culturing the streptococci at 22° C. Cultures which, when grown at 37° C. yield M substance in extracts, do not produce the enzyme. 4. Human and rabbit fibrin are attacked and streptococcal fibrinolysin is also inactivated by the enzyme. Other susceptible substrates include casein, milk, gelatin, and benzoyl-l-arginineamide but not l-leucylglycylglycine. 5. The general properties of the enzyme resemble those of papain and some of the cathepsins: It is active under the reducing conditions produced in broth cultures by the presence of living bacteria; it is also activated by substances which reduce disulfide to sulfhydryl groups, e.g. potassium cyanide, cysteine, glutathione, and thioglycollic acid, but it is not activated by ascorbic acid. The enzyme is inactivated by iodoacetic acid and also by normal rabbit or mouse serum.

The role of amylolytic and proteolytic enzyme activities of vegetables, fruits, and edible fungi in flavor enhancement during cooking

2020 ◽  
Vol 22 ◽  
pp. 100264
Author(s):  
Saki Oosone ◽  
Ayaka Kashiwaba ◽  
Naoyuki Yanagihara ◽  
Jun Yoshikawa ◽  
Yutaka Kashiwagi ◽  
...  
Keyword(s):  
Enzyme Activities ◽  
Proteolytic Enzyme ◽  
Edible Fungi

Purification and properties of an extracellular proteolytic enzyme fromBacillus cereus

1973 ◽  
Vol 40 (3) ◽  
pp. 427-440 ◽  
Author(s):  
M. A. Islam ◽  
J. M. V. Blanshard
Keyword(s):  
Metal Ion ◽  
Absorption Maximum ◽  
Proteolytic Enzyme ◽  
Heavy Metal Ions ◽  
Freeze Drying ◽  
Deae Cellulose ◽  
Milk Clotting ◽  
Purification And Properties ◽  
Extracellular Proteolytic Enzyme ◽  
Metal Ion Activation

SummaryA milk-clotting proteolytic enzyme was isolated and purified from the culture filtrate ofBacillus cereusstrain x29 by fractionation with acetone or ammonium sulphate and subsequent column chromatography employing DEAE cellulose and DEAE Sephadex. The purified enzyme was found to be homogeneous by acrylamide gel electrophoresis from pH 3·5 to 8·6, with, a molecular weight of about 50000. The single absorption maximum of the native enzyme was at 277 nm and the value ofat 280 nm was 7·79. Purification resulted in a 9-fold enhancement of activity with 24 % yield. The optimum activity of the enzyme was at pH 8·0 at 40 °C with casein as the substrate. The enzyme was found to be most stable at pH 6·0 and was stable to freezing and freeze-drying. Heavy metal ions were found to inactivate the enzyme, but no metal ion activation was found. Enzyme activity was inhibited irreversibly by EDTA and reversibly by 1,10-phenanthroline. The enzyme has been identified as a Zn-containing neutral protease.

Sign in / Sign up

Export Citation Format

Share Document