ACTION OF ENZYMES ON HUMAN PLACENTA

The action of proteolytic enzymes on insulin.

The action of enzymes on chlorophenylalanines.

It is evident from this investigation that the bile pigment precursor content ofhuman erythrocytes is not greater than that associated with the corresponding amount of crystalline oxyhaemoglobin. Such a result could arise if either of two quite different conditions obtain. The minute yields of bile pigment might be caused artificially by the drastic chemical processes involved. Alternatively, b...

Cc . the Action of Dyestuffs on Enzymes

The method of investigation consisted in submitting a preparation of urease to the action of a dyestuff at PHI 7-4 and at 450 for a given time, usually 30 mins. or 1 hour, and in then determining the activity of the enzyme by estimating the amount of ammonia produced at 450 in a given time from a 0 3 % solution of urea. 1 cc. of the enzyme preparation was added to 2 cc. M/15 phosphate buffer so...

The Action of Enzymes on Rhodopsin

The effects have been examined of chymotrypsin, pepsin, trypsin, and pancreatic lipase on cattle rhodopsin in digitonin solution. The digestion of rhodopsin by chymotrypsin was measured by the hydrolysis of peptide bonds (formol titration), changes in pH, and bleaching. The digestion proceeds in two stages: an initial rapid hydrolysis which exposes about 30 amino groups per molecule, without bl...

Action of Formaldehyde on Enzymes and on Certain Pboteids

THE FOLLOWING GENERAL CONCLUSIONS MAY BE DRAWN FROM THE PRECEDING WORK: Fibrin is altered by formaldehyde and is then less easily digested by pepsin and by trypsin. Papaïn is apparently unable to digest fibrin even when this is exposed to very weak formaldehyde (1:1000) for a very short time. The casein of milk, on contact with formaldehyde, undergoes rapid alteration and is as a result not coa...