alpha-Galactosidase of the Marine Bacterium Pseudoalteromonas sp. KMM 701

I. Yu. Bakunina^1*, V. V. Sova¹, O. I. Nedashkovskaya¹, R. A. Kuhlmann², L. M. Likhosherstov³, M. D. Martynova³, V. V. Mihailov¹, and L. A. Elyakova¹

¹Pacific Institute of Bioorganic Chemistry, Far Eastern Division of the Russian Academy of Sciences, pr. 100-letiya Vladivostoka 159, Vladivostok, 690022 Russia; fax: (4232) 31-4050; E-mail: bakun@piboc.marine.su

²Hematology Research Center, Russian Academy of Medical Sciences, Moscow, 125167 Russia

³Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Leninskii pr. 47, Moscow, 117334 Russia

^* To whom correspondence should be addressed.

Received November 20, 1997; Revision received January 8, 1998

---

An alpha-galactosidase that inactivates the group specificity of B erythrocytes (group III) of human blood and does not affect A erythrocytes (group II) was isolated from the marine bacterium Pseudoalteromonas sp. KMM 701. The enzyme preparation did not contain lectin, hemolytic, sialidase, endoglycanase, or glycosidase activities. The enzyme is stable at 20°C for 24 h, has pH optimum for catalysis within the range of 6.7-7.7, and is stable to high concentrations of NaCl. It is 4-fold more efficient than the alpha-galactosidase from green coffee beans. At pH 7.0 the K_m for p-nitrophenyl-alpha-D-galactopyranoside is 0.29 mM. The molecular weight of the enzyme determined by gel-filtration is 195 ± 5 kD. The alpha-galactosidase is denatured by urea and guanidine hydrochloride. Its activity does not depend on the presence of metal ions. It contains a sulfhydryl group essential for its catalytic activity.

---

KEY WORDS: alpha-galactosidase, Pseudoalteromonas, erythrocyte transformation

---