Enzymes Discussed at Appleton A STAFF REPORT
Above. Ward W. Pigrnan9 general chairman of meeting. Right. II. J. Koepsell, and A. J. Wiley, vice chairman of the Northeast Wisconsin Section, ACS
%^& t>"g
JL HE importance of enzymes and the increased knowledge concerning them was impressed upon a group of about 90 technical men who attended the recent oneday symposium devoted entirely to that subject held at the Institute of Paper Chemistry at Appleton, Wis., March 20. The meeting was sponsored jointly by the Northeast Wisconsin Section of the AMERICAN CHEMICAL SOCIETY and
the
Valley
Microbiological Society. Amylases were the subjects of two papers delivered by W. W. Pigman of the Institute of Paper Chemistry and Eric Kneen of the Kurth Malting Co. On the basis of the nature of products formed, Dr. Pigman divided the amylases into four classes: beta-amylases, liquefying amylases, Bacillus macerans amylase, and phosphorylases. Beta-amylase, he said, acts on the ends of straight chains by the removal of maltose units, and amylose is converted completely to maltose. The liquefying amylases were noted to be the commercially important type. These enzymes appear to break down starch quickly into fragments containing four to eight glucose residues. Bacillus macerans enzymes appear to be unique in converting starches to cyclic dextrins containing six or seven glucose units. The phosphorylases,
occurring in yeast and muscle and other tissues synthesize amylopectin, glycogen, and amylose from glucose 1-phosphate. Dr. Kneen divided the amylases into several types based on starch-degrading properties. Most of these, he said, may be placed in two classes, the starch-saccharifying or beta-amylases group and the starch liquefying or alpha-anrylases group. In addition, he mentioned special types such as that of Bacillus macerans and the phosphorylases. The limit of the conversion of starch by beta-amylases is achieved at approximately 60% conversion to maltose with a stable residue of a characteristic high molecular dextrin. Some of the alpha-amylases, Dr. Kneen said, release a minimum of sugar during their action, wrhile others, either complex in nature or accompanied by supplementary enzymes, permit relatively high conversion to sugar in the post-dextrinization stage of starch hydrolysis. The respiratory enzymes were discussed by Nelson Rodgers of the Western Condensing Co. and H. J. Koepsell of the Northern Regional Research Laboratory. Dr. Rodgers traced the respiratory processes through the activity of enzymes, showing their part in the stepwise liberation of energy ancl its transmission and
Left. Eric Kneen, Kurth Malting Co.; W. W. Moyer, A. E. Staley Mfg. Co.; and S. M. Cantor, Corn Products Refining Co. Right. A. M. Hanson, president
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storage in the for:m of bond energy. These respiratory enzyr^ies, he said, area heterogeneous group vcrhich are cellular in activity and :are Found ia all cells. The participation of phosphate in many respiratory processes, apparently as a means for converting respiratory free-energy release into a for-rn capable of use by the organism, was pointed out- by Dr. Koepsell. Recent tlheories w e r e developed which explain this functior*. as attachment of phosphate to Lntermediajry metabolites, thus forming lialkages possessing low potential hydrolytic energy, followed by the concentrating of energy in. these linkages by various metabolic changes, forming phosphate bonds rich in energy for use in cellular worlc. The general ^properties, classification, and occurrence o f enzymes was described by John W. Appling of "tlie Institute of Paper Chemistry who liste-d various properties and their ixnplicatioris regarding the protein nature of enzymes. "CommercialEnzymes" was the subject of C. E. Denoo»n, Jr., wlio described a number of coin_xnercial processes which are possible through conventional chemical means bxit wbdeh mayfc>eaccomplished through enzymartic reactions under sufficiently mild conclitions so fchat other materials present are "unaffected.. Curtis S. Walseth, of t h e Institute of Paper Chemistr-y, disciassed cellulases, enzymes occurring in fun^i, bacteria, and intestinal tracts of lower animals and insects, whicti are capable of hydrolyzing cellulose to» sugars. He mentioned the saccharineation of wood residues a s a potential application. Hemicellulases was the subject of A. P. Yundt of t h e Raper Institute, a,nd the metal-containing oxidizirtg enzymes and the proteases were the respective topics of H. N. Little a-nd Merlin H. Peterson of the University o f Wisconsin.
of Valley Microbiological Sociezty, co-sponsor of the meeting; Louis Veler, secretary of &he Northeast Wisconsin Section; Paizl Tr~uttschel-, choir man
1947
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