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Improved specificity toward substrates with positively charged side chains by site-directed mutagenesis of the L-lactate dehydrogenase of Bacillus stearothermophilus


, : Improved specificity toward substrates with positively charged side chains by site-directed mutagenesis of the L-lactate dehydrogenase of Bacillus stearothermophilus. Biochemistry. 34(13): 4225-4230

The substrate specificities of L-alpha-hydroxy acid dehydrogenases, including L-lactate dehydrogenases (L-LDH's), can often be quite broad. However, an LDH with high catalytic activity toward alpha-keto acids with positively charged side chains, such as those containing ammonium groups, has not been described, even though there is evidence from metabolic studies that a natural dehydrogenase with such activity might exist in Nature. L-omega-Amino-alpha-hydroxy acids are important intermediates in the synthesis of pharmacologically active compounds, and enzymatic reduction of omega-amino-alpha-keto acids represents an attractive route to these compounds. Graphics analysis indicated that introduction of acidic amino acids at position 102 of the L-LDH of Bacillus stearothermophilus (BSLDH) would favor binding of such side chain ammonium groups. Accordingly, Q102E and Q102D mutant BSLDH's were constructed and the steady state kinetic parameters determined for these mutants for a broad range of alpha-keto acids, including omega-amino-alpha-keto acids. The results obtained show that, compared to WT-BSLDH, these mutants show up to 25-fold improvements in k-cat/K-m values for omega-amino-alpha-keto acid substrates.

US$19.90

PMID: 7703235

DOI: 10.1021/bi00013a011


Other references

Minagawa, H., 1963: Studies On The Surgical Management Of Cerebral Apoplexy. I. The Effect Of Experimental Intracerebral Hemorrhage On Glutamic Oxalacetic Transaminase And Lactic Dehydrogenase In Serum And Cerebrospinal Fluid. Sapporo Igaku Zasshi. Sapporo Medical Journal 23: 50-63

Olmedilla, Bña.; Granado, F.; Southon, S.; Wright, A.J.A.; Blanco, I.; Gil-Martinez, E.; van den Berg, H.; Thurnham, D.; Corridan, B.; Chopra, M.; Hininger, I., 2002: A European multicentre, placebo-controlled supplementation study with alpha-tocopherol, carotene-rich palm oil, lutein or lycopene: analysis of serum responses. Increased levels of oxidative stress have been implicated in tissue damage and the development of chronic diseases, and dietary antioxidants may reduce the risk of oxidative tissue damage. As part of a European multicentre project, several studies...

Holmes, B.F.; Kurth-Kraczek, E.J.; Winder, W.W., 1999: Chronic activation of 5'-AMP-activated protein kinase increases GLUT-4, hexokinase, and glycogen in muscle. This study was designed to determine whether chronic chemical activation of AMP-activated protein kinase (AMPK) would increase glucose transporter GLUT-4 and hexokinase in muscles similarly to periodic elevation of AMPK that accompanies endurance...

Makarevich, V.G.; Smirnova, G.L., 1966: Synthesis of vitamin B12, 3 and chlortetracycline by some strains of Actinomyces aureofaciens. Different compounds of nutritional media were investigated in the connection with its action on the synthesis of vitamin Bi~ and antibiotics in the cultures of strains LSB-16 and LSB-22C1. These strains were derived from Actinomyces aureofaciens 1...

Chang S.C.; Woods C.W., 1979: Metabolism of carbon 14 labeled penfluron in the house fly musca domestica. 14C-penfluron was used in the study of its metabolism in M. domestica L. After injection of 298,000 dpm (11 .mu.g)/female, radioactivity distribution was determined and percentages were calculated on the basis of total injected amount. At 72 h pos...

Bhargava, D.S.; Sheldarkar, S.B., 1992: Effects of adsorbent dose and size on phosphate-removal from wastewaters. Laboratory scale production of rinsed tamarind nutshell activated carbon (TNSAC) was done by the method of single stage chemical activation, with zinc chloride as an activation agent. Using this adsorbent, adsorption studies were conducted in agit...

Quan, Y.; Du, J.; Wang, X., 2007: High glucose stimulates GRO secretion from rat microglia via ROS, PKC, and NF-kappaB pathways. Hyperglycemia causes direct neuronal damage in diabetic encephalopathy. Microglia have been found to be activated in diabetic encephalopathy, presumably mediating and amplifying neuron degeneration. Chemokine IL-8 plays an important role in the pa...

Little, Elbert L., 1963: Card key to the families of tropical American trees. A description is given of the perforated card key for the identification of families of Latin-American tropical trees. Its advantages and disadvantages are discussed. This 3-dimensional key can be used with incomplete material, begin with any char...

Woznicki, A.; Greger, J., 1993: Reorientation time of DNA molecules in pulsed-field gel electrophoresis. The precise determination of the influence of an electric field strength E on the resolution of DNA molecules during a pulsed-field gel electrophoresis shows that the maximal molecular size Nmax of still resolved DNA molecules is described by the...

Sun J.H., 1987: Endoscopic esophageal varix ligation evl in acute variceal hemorrhage. Hepatology: 1062