Emulsin preparation from almonds

A glycopeptide prepared from stem bromelain has been AT-[ Clacetylated. The peptide-carbohydrate linkage was cleaved with an enzyme preparation from almond emulsin to yield an intact oligosaccharide unit containing two moles of 2-acetamido-2-deoxy-D-glucose and a pentapeptide. 

A similar method is based on the enzymic hydrolysis of the yeast nucleic acid (4 ). Emulsins prepared from sweet almonds, alfalfa seeds, and many sprouted seeds hydrolyze polynucleotides (nucleic acids) to the nucleosides. Guanosine (V-ribosyl-guanine) is produced almost quantitatively and adenosine picrate (picrate of V-ribosyl-adenine) is likewise obtained in high yield. As in the earlier methods, the nucleosides are hydrolyzed by acids to give D-ribose. 

The classical source for melibiase is almond emulsin. The melibiase activity in almond emulsin is low, and it is easily and preferentially destroyed by alcohol precipitation and by other common preparative steps. Almond melibiase preparations are quite free from invertase,16 and hence they are of special value in those situations where an invertase-free... 

An affinity chromatographic method developed for the purification of a-L-fucosidase I from almond emulsin was based on modified agarose derivatized with 6-aminohexanoyl-lacto-A-fucopentaosylamine. The final enzyme preparation was free from other glycoside hydrolases. 

From almond emulsin, enzymes with a jS-glucosidase value as high as 16 have been prepared. (The ordinary almond emulsins have a value of 1 or less.) The properties of such preparations have been studied by Helferich and associates (16). The elementary composition agrees with that of protein substances, but the hydrogen content is somewhat greater than usual. The protein nature of the material also agrees with the action of the anions of neutral salts on the enzymic activity since the order of activation by... 

Almond emulsin is prepared from defatted crushed almonds by extraction with water and precipitation of the extracts with alcohol. The dried powder is known as almond emulsin. A preparation of considerably more activity is obtained by treatment of the almond meal with zinc sulfate solution and precipitation of the enzymes from solution by the addition of tannin. The tannin is separated from the enzyme by extraction of the precipitate with acetone, and the solid residue is the Rohferment of Helferich 23) which has been used for many of the studies of the specificities of the enzyme components of almond emulsin. The Rohferment usually has a /S-gluco-sidase value of about 1. 

Calf spleen and liver 66), Escherichia coli 67), and almond emulsin 68a, h) are the sources of the most-studied preparations of jS-glucuroni-dases. Commercial preparations from animal tissues are available 69) ... 

Results are expressed as fig of p-nitrophenol liberated per g of seed from 6 mM p-nitrophenyl a-D-mannoside in 1 hr at 37° and pH 5. Coarsely ground beans. Defatted sweet-almond meal. A commercial /3-D-glucosidase preparation purified from emulsin. a-D-Mannosidase activity is given per g of purified material. 

The first evidence for the presence of an a-D-mannosyl link in ovalbumin glycopeptides was provided by the action of almond emulsin,101,102 although the absence of /3-D-mannosidase from the enzyme preparation was not confirmed until later.103 The presence of 2-acetamido-2-deoxy-/M>glucosidase in emulsin left doubt as to the terminal position of all of the D-mannose released. 

Pigman has prepared crystalline u-altrose from neolactose by cleavage of the disaccharide with sweet almond emulsin, followed by removal of the D-galactose by fermentation with yeast. This procedure avoids the transformation of any n-altrose to u-altrosan, the non-reducing anhydride which is formed to the extent of 57% in the hydrolysis of neolactose by acids. 

It is usually separated as the octaacetate. The hydrogenation of hepta-0-acetylamygdalin 5) and the isolation of the octaacetate of gentiobiose, from the acetylated mother liquors ( hydro ) of the preparation of D-glu-cose from starch, have been suggested for the preparation of the disaccharide. The best method, however, is probably the synthetic method of Hel-ferich as modified by Reynolds and Evans and described below. Enzymic s3mthesis by the action of almond emulsin on D-glucose is also recommended 46). 

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