Physico-chemical and Enzymatic Properties of Purified Glucose Isomerases fromStreptomyces olivochromogenesandBacillus stearothermophilus

Purification and Properties ofd-Xylose Isomerase from AlkalophilicBacillusNo. KX-6

“…14 -19 ) Inactivation by Hg2 + suggests the presence ofa thiol group, although other thiol agents such as pchloromercuribenzoate were ineffective. The physical properties of the enzyme were very similar to those of Bacillus coagu/ans 15 ) and Bacillus stearothermophilus 16 ) except that Bacillus KX-6 enzyme dissociated into 2 subunits. Another distinctive feature of enzyme was its low 'molecular weight.…”

Purification and characterization of thermostable glucose isomerase from Clostridium thermosulfurogenes and Thermoanaerobacter strain B6A

“…The optimum pH for the glucose-isomerizing activity of C. thermosulfurogenes and Thermoanaerobacter was 7.0-7.5, which was similar to those of the enzymes from B. coagulans (Danno, 1970b) and A. missouriensis (Scallet et al, 1974), and was lower than those (pH 8.0-10.0) of enzymes from Streptomyces phaechromogenes (Tsumura & Sato, 1965), S. griseofuscus (Kasumi et al,198 1a) and S. olivochromogenes (Suekane et al, 1978). The enzymes from both thermoanaerobes were stable within the pH range 5.5-11.0, and displayed pI values of 4.9 and 4.8.…”

“…10 % of total protein) in the cell extract, and purification of the enzymes was relatively simple. The abundance of this enzyme in the cell extracts may be due to the fact that the enzyme had a relatively low kcat and high K,, which is typical of xylose isomerase (Suekane et al, 1978;Antrim et al, 1979), and perhaps the organism needed to overproduce this enzyme, which may be rate-limiting for growth on xylose. The growth rate of these bacteria is faster on glucose than on xylose (Schink & Zeikus, 1983;Weimer et al, 1984).…”

“…Glucose isomerases characterized from Streptomyces species (Takasaki et al, 1969;Kasumi et al, 1981b), Arthrobacter (Henrik et al, 1989), Bacillus coagulans (Danno, 1970a) and Flavobacterium arborescens (Boguslawski, 1983) (Yamanaka, 1968;Takasaki et al, 1969;Danno, 1970a;Suekane et al, 1978). Glucose isomerases from E. coli (Tucker et al, 1988), alkalophilic Bacillus (Kwon et al, 1987), Actinoplanes missouriensis (Gong et al, 1980) and Streptomyces olivochromogenes (Suekane et al, 1978) are dimers, with Mr values of 80000-120000.…”

Subunit Structure of Glucose Isomerase fromStreptomyces griseofuscus, S-41

“…The enzyme from Bacillus coagulans, HN-68 6 ) (molecular weight ·175,000) is reported to dissociate with sodium dodecyl sulfate into three or four subunits with equal molecular weights of 49,000. Xylose isomerase from Streptomyces albus 4 ) (molecular weight 165,000) is a tetramer, composed of four identical or very similar polypeptide chains of molecular weight 41,500, while glucose isomerase prepared from Streptomyces olivochromogenes 5 ) (molecular weight 117,000) is reported to be a dimer.…”