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The gene encoding vanadium-dependent bromoperoxidase (V-BPO) was cloned for the first time from the red alga Laurencia saitoi, which produces pharmaceutically promising brominated diterpenoids and triterpenoids. The molecular weight of V-BPO from L. saitoi (LsVBPO1) was the highest (77.0 kDa) among previously reported V-BPOs from Laurencia with a peptide insertion Asn194-Ser221 containing short Gln repeats. It shares approximately 60% amino acid sequence identity with V-BPOs from L. nipponica (LnVBPO1 and LnVBPO2) and L. okamurae (LoVBPO1a and LoVBPO2a). Heterologously expressed LsVBPO1 in Escherichia coli was partially purified and exhibited low but significant bromination activity of 38 U mg−1 protein using monochlorodimedone. The pH optimum was 8.0, which was more alkaline than that for LnVBPOs and LoVBPO2a (pH 7.0). The Km for H2O2 was 0.04 mM, comparable to LnVBPO1 (0.026 mM), LnVBPO2 (0.025 mM), and LoVBPO2a (0.014 mM). LsVPBO1 retained its bromination activity until 45 °C for 20 min. When incubated at 55 °C for 20 min, catalytic activity decreased rapidly, as shown for LnVBPO1 and LoVBPO2a (retained at 45 °C, decreased at 55 °C) and LnVBPO2 (retained at 55 °C, decreased at 65 °C). Unlike other V-BPOs from Laurencia (LnVBPO1, LnVBPO2, and LoVBPO2a), dialysis and concentration during purification process were rapidly inactivated LsVBPO1, suggesting its structural instability. [ABSTRACT FROM AUTHOR]

Seven parguerane diterpenes: 15-bromo-2,7,19-triacetoxyparguer-9(11)-en-16-ol (1), 15-bromo-2,7,16,19-tetraacetoxyparguer-9(11)-ene (2), 15-bromo-2,19-diacetoxyparguer-9(11)-en-7,16-diol (3), 15-bromo-2,16,19-triacetoxyparguer-9(11)-en-7-ol (4), 15-bromo-2,16-diacetoxyparguer-9(11)-en-7-ol (5), 15-bromoparguer-9(11)-en-16-ol (6), 15-bromoparguer-7-en-16-ol (7), two polyether triterpenes: thyrsiferol (8) and thyrsiferyl 23-acetate (9), and one C15-acetogenin, neolaurallene (10), were isolated from a sample of marine red alga Laurencia saitoi collected off the coast of Yantai. Their structures were established by detailed NMR spectroscopic analysis and comparison with literature data.

Cites a study on the characterization of an alga specie Laurencia saitoi Perestenko in Japan. Growth of the alga in channels unexposed to desiccation; Features of the alga's attachment; Effect of environmental conditions on development of the first-order branches of the species.