scholarly journals Kinetic properties and substrate specificities of two cellulases from auxin-treated pea epicotyls.

1977 ◽  
Vol 252 (4) ◽  
pp. 1402-1407
Author(s):  
Y S Wong ◽  
G B Fincher ◽  
G A Maclachlan
Keyword(s):  
Kinetic Properties ◽  
Substrate Specificities

scholarly journals 5′-Nucleotidases in rat heart. Evidence for the occurrence of two soluble enzymes with different substrate specificities

1988 ◽  
Vol 253 (1) ◽  
pp. 117-121 ◽  
Author(s):  
V L Truong ◽  
A R Collinson ◽  
J M Lowenstein
Keyword(s):  
Rat Heart ◽  
Work Load ◽  
Soluble Proteins ◽  
High Load ◽  
Kinetic Properties ◽  
Substrate Specificities ◽  
Metabolic Stresses ◽  
Soluble Enzymes

Chromatography of soluble proteins from rat heart on phosphocellulose columns separates two 5′-nucleotidases. The first to emerge from the column shows a preference for AMP over IMP as substrate, whereas the second shows a preference for IMP over AMP. The properties of the IMP-preferring enzyme, including the conditions under which it is eluted from phosphocellulose columns, show it to be the enzyme studied by Itoh, Oka & Ozasa [Biochem. J. (1986) 235, 847-851]. The kinetic properties of the AMP-preferring enzyme indicate that it is likely to be the enzyme responsible for the production of adenosine under conditions of hypoxia and increased work load, and with metabolic stresses such as a high load of acetate.

scholarly journals Functional Analysis of Two l-Arabinose Transporters from Filamentous Fungi Reveals Promising Characteristics for Improved Pentose Utilization in Saccharomyces cerevisiae

2015 ◽  
Vol 81 (12) ◽  
pp. 4062-4070 ◽  
Author(s):  
Jingen Li ◽  
Jing Xu ◽  
Pengli Cai ◽  
Bang Wang ◽  
Yanhe Ma ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sugar Transport ◽  
Biomass Accumulation ◽  
Kinetic Properties ◽  
High Identity ◽  
Content Type ◽  
Substrate Specificities ◽  
Dry Cell Weight ◽  
Dry Cell

ABSTRACTLimited uptake is one of the bottlenecks forl-arabinose fermentation from lignocellulosic hydrolysates in engineeredSaccharomyces cerevisiae. This study characterized two novell-arabinose transporters, LAT-1 fromNeurospora crassaand MtLAT-1 fromMyceliophthora thermophila. Although the two proteins share high identity (about 83%), they display different substrate specificities. Sugar transport assays using theS. cerevisiaestrain EBY.VW4000 indicated that LAT-1 accepts a broad substrate spectrum. In contrast, MtLAT-1 appeared much more specific forl-arabinose. Determination of the kinetic properties of both transporters revealed that theKmvalues of LAT-1 and MtLAT-1 forl-arabinose were 58.12 ± 4.06 mM and 29.39 ± 3.60 mM, respectively, with correspondingVmaxvalues of 116.7 ± 3.0 mmol/h/g dry cell weight (DCW) and 10.29 ± 0.35 mmol/h/g DCW, respectively. In addition, both transporters were found to use a proton-coupled symport mechanism and showed only partial inhibition byd-glucose duringl-arabinose uptake. Moreover, LAT-1 and MtLAT-1 were expressed in theS. cerevisiaestrain BSW2AP containing anl-arabinose metabolic pathway. Both recombinant strains exhibited much fasterl-arabinose utilization, greater biomass accumulation, and higher ethanol production than the control strain. In conclusion, because of higher maximum velocities and reduced inhibition byd-glucose, the genes for the two characterized transporters are promising targets for improvedl-arabinose utilization and fermentation inS. cerevisiae.

Kinetic properties and substrate specificities of two recombinant human N-acetylglucosaminyltransferase-IV isozymes

2006 ◽  
Vol 23 (7-8) ◽  
pp. 473-480 ◽  
Author(s):  
Suguru Oguri ◽  
Aruto Yoshida ◽  
Mari T. Minowa ◽  
Makoto Takeuchi
Keyword(s):  
Kinetic Properties ◽  
Substrate Specificities

Chromatographic Isolation of the LDH-Isoenzymes of Human Blood Platelets and an Investigation of Their Enzyme Kinetics

1968 ◽  
Vol 20 (03/04) ◽  
pp. 301-313 ◽  
Author(s):  
W Schneider ◽  
K Schumacher ◽  
B Thiede ◽  
R Gross
Keyword(s):  
Human Blood ◽  
Blood Platelets ◽  
Deae Cellulose ◽  
Order Reaction ◽  
Kinetic Properties ◽  
Ldh Isoenzymes ◽  
Kinetic Investigations ◽  
Substrate Concentrations ◽  
Chromatographic Isolation ◽  
Human Blood Platelets

SummaryThe LDH-isoenzymes of human blood platelets show a distinct predominance of the isoenzymes 2 and 3 upon chromatography on DEAE-cellulose. Small amounts of LDH-1 are also present, while only traces of LDH-4 and -5 can be detected.Enzyme kinetic investigations of the principal isoenzymes LDH-1, -2 and -3 clearly show that the differences in inhibition constants with pyruvate as substrate which are demonstrable at 25° largely disappear at 37°. On the other hand, the differences among the isoenzymes in their affinity for pyruvate and lactate as substrate as well as in with respect to the optimal substrate concentrations of pyruvate are more marked at 37° than at 25°. Also, the type of inhibition found with lactate as substrate is increasingly the expression of a higher order reaction in going from LDH-1 to LDH-3. A dependence of the LDH distribution pattern upon the metabolism of the cell is discussed. A comparison of our results with thrombocytes with those of other workers with erythrocytes and leucocytes makes it unlikely that the LDH pattern is directly dependent upon the existence of an oxidative metabolism. Rather, the redox potential of the cell could be of importance for the nature of the pattern of isoenzymes and for their differing kinetic properties.

Effect of CeO$lt;inf$gt;2$lt;/inf$gt;-based Solid Solutions on Hydrogen Storage Kinetic Properties of Mg$lt;inf$gt;2$lt;/inf$gt;Ni Alloy

2014 ◽  
Vol 29 (12) ◽  
pp. 1241
Author(s):  
ZHANG Guo-Fang ◽  
ZHANG Yang-Huan ◽  
LIU Zhuo-Cheng ◽  
XU Jian-Yi ◽  
ZHANG Yin
Keyword(s):  
Hydrogen Storage ◽  
Solid Solutions ◽  
Kinetic Properties ◽  
Ni Alloy
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