Canine submandibular-gland hyaluronidase. Purification and properties

Pyridoxal arsenate as a prosthetic group for aspartate aminotransferase

The apoenzyme of aspartate aminotransferase formed a stable, active holoenzyme on treatment with pyridoxal in the presence of arsenate.

Identification of the reaction products of the purified hyaluronidase from stonefish (Synanceja horrida) venom

Recently we purified to homogeneity hyaluronidase from stonefish (Synanceja horrida) venom, for the first time from a marine source [Poh, Yuen, Chung & Khoo (1992) Comp. Biochem. Physiol., in the press]. In the present study the reaction products of the hyaluronidase purified from stonefish venom were analysed. It produced tetra-, hexa-, octa- and deca-saccharides as major end products, but not disaccharides. The structure of the tetrasaccharide product was determined by enzymic analysis, in conjunction with h.p.l.c. and by 1H n.m.r., as GlcA beta 1-3GlcNAc beta 1-4GlcA beta 1-3GlcNAc. Chemical shifts of the structural-reporter-group protons of the constituent monosaccharides for the tetrasaccharide have been assigned. The enzyme did not act on chondroitin sulphate or dermatan sulphate. The results indicate that the stonefish hyaluronidase is an endo-beta-N-acetylglucosaminidase specific for hyaluronate.

Canine submandibular-gland hyaluronidase. Identification and subcellular distribution

1. Submandibular glands from four species of mammal have been shown to contain a hyaluronidase active at acid pH; glands from dog and cat had a much higher content of this enzyme than has been found in other sources. 2. Product formation from hyaluronate after 24hr. incubation was almost the same as with testicular hyaluronidase, indicating that the enzyme is an endo-poly-beta-hexosaminidase. 3. When submandibular-gland homogenates were fractionated by the scheme developed for liver by de Duve, Pressman, Gianetto, Wattiaux & Appelmans (1955), all the enzymes assayed, except cytochrome c oxidase, were found to occur partly in the soluble fraction and partly in the particulate fractions. Among the particular fractions, the highest specific activity was found in the heavy-mitochondrial fraction for cytochrome c oxidase, in the microsomal fraction for alkaline phosphatase and in the light-mitochondrial fraction for acid phosphatase, beta-N-acetylhexosaminidase and acid-active hyaluronidase. 4. Release of the enzyme activity from the sedimentable fractions occurred in 0.1% Triton X-100 or after high-speed homogenization. 5. Stimulation of dogs by pilocarpine was found to decrease the hyaluronidase content of the submandibular gland by 5% and to cause the occurrence of a corresponding amount of acid-active hyaluronidase in the submandibular saliva. 6. The results are discussed in relation to the subcellular localization of hyaluronidase.