Activation of Bacillus licheniformis α-amylase through a disorder→order transition of the substrate-binding site mediated by a calcium–sodium–calcium metal triad

Machius, Mischa; Declerck, Nathalie; Huber, Robert; Wiegand, Georg

doi:10.1016/s0969-2126(98)00032-x

Cited by 231 publications

(217 citation statements)

References 42 publications

(69 reference statements)

Supporting

Mentioning

203

Contrasting

Unclassified

Order By: Relevance

“…Ca# + is required for the structural integrity of α-amylases such as AmyL [23][24][25]. Consistent with the structural topologies of other α-amylases and amylolytic enzymes, the structure of AmyL has three distinct domains [24].…”

Section: Introductionmentioning

confidence: 63%

“…The more recent Ca# + -containing structure of AmyL (1BLI ; see [25]) was not used, because the finite difference PoissonBoltzmann (FDPB) electrostatic calculations used currently do not include heteroatoms. The sequence alignment of the α-amylases ( Figure 1) is largely unequivocal and residues corresponding to 182-192 of AmyL (which are not resolved in 1BPL) were deleted.…”

Section: Spectroscopy and Homology Modelling Of α-Amylasesmentioning

confidence: 99%

“…Consistent with the structural topologies of other α-amylases and amylolytic enzymes, the structure of AmyL has three distinct domains [24]. The central N-terminal domain (domain A, residues 1-101 and 203-396) of AmyL is the most conserved domain throughout the α-amylases and is composed of a (β\α) ) barrel, with the active site and a conserved Ca# + -binding site (Ca I) located on the C-terminal side of the barrel [24,25]. Domain B is a protrusion from domain A and is composed of a two long central β-strands (residues 111-121 and 133-140) wound around each other in a helical manner and four antiparallel β-strands.…”

Section: Introductionmentioning

confidence: 99%

“…Domain B is a protrusion from domain A and is composed of a two long central β-strands (residues 111-121 and 133-140) wound around each other in a helical manner and four antiparallel β-strands. An α-helix found in the majority of α-amylases is replaced in AmyL by a stem-loop structure which provides the majority of the ligands for a novel linear metal-ion array, the Ca I-Na-Ca II triad [25]. The substrate-binding cleft is located in the interface between domains A and B, the structure of which is stabilized by the Ca I-Na-Ca II triad.…”

Section: Introductionmentioning

confidence: 99%

“…The substrate-binding cleft is located in the interface between domains A and B, the structure of which is stabilized by the Ca I-Na-Ca II triad. The C-terminal domain of AmyL (domain C, residues 393-483) contains a Greek-key motif, and an additional Ca# + -binding site (Ca III) is located at the interface of this domain with domain A and represents a second anchor point between these two domains [25].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

The influence of secretory-protein charge on late stages of secretion from the Gram-positive bacterium Bacillus subtilis

Stephenson

Jensen

Jørgensen

et al. 2000

Biochemical Journal

View full text Add to dashboard Cite

Following their secretion across the cytoplasmic membrane, processed secretory proteins of Bacillus subtilis must fold into their native conformation prior to translocation through the cell wall and release into the culture medium. The rate and efficiency of folding are critical in determining the yields of intact secretory proteins. The B. subtilis membrane is surrounded by a thick cell wall comprising a heteropolymeric matrix of peptidoglycan and anionic polymers. The latter confer a high density of negative charge on the wall, endowing it with ion-exchange properties, and secretory proteins destined for the culture medium must traverse the wall as the last stage in the export process. To determine the influence of charge on late stages in the secretion of proteins from this bacterium, we have used sequence data from two related α-amylases, to engineer the net charge of AmyL, an α-amylase from Bacillus licheniformis that is normally secreted efficiently from B. subtilis. While AmyL has a pI of 7.0, chimaeric enzymes with pI values of 5.0 and 10.0 were produced and characterized. Despite the engineered changes to their physico-chemical properties, the chimaeric enzymes retained many of the enzymic characteristics of AmyL. We show that the positively charged protein interacts with the cell wall in a manner that influences its secretion.

show abstract

Section: Introductionmentioning

confidence: 63%

Section: Spectroscopy and Homology Modelling Of α-Amylasesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The influence of secretory-protein charge on late stages of secretion from the Gram-positive bacterium Bacillus subtilis

Stephenson

Jensen

Jørgensen

et al. 2000

Biochemical Journal

View full text Add to dashboard Cite

show abstract

The effect of process conditions on the ?-amylolytic hydrolysis of amylopectin potato starch: An experimental design approach

Marchal

Jonkers

Franke³

et al. 1999

Biotechnol. Bioeng.

View full text Add to dashboard Cite

The hydrolysis of amylopectin potato starch with Bacillus licheniformis α‐amylase (Maxamyl) was studied under industrially relevant conditions (i.e. high dry‐weight concentrations). The following ranges of process conditions were chosen and investigated by means of an experimental design: pH [5.6–7.6]; calcium addition [0–120 μg/g]; temperature [63–97°C]; dry‐weight concentration [3–37% [w/w]]; enzyme dosage [27.6–372.4 μL/kg] and stirring [0–200 rpm]. The rate of hydrolysis was followed as a function of the theoretical dextrose equivalent. The highest rate (at a dextrose equivalent of 10) was observed at high temperature (90°C) and low pH (6). At a higher pH (7.2), the maximum temperature of hydrolysis shifted to a lower value. Also, high levels of calcium resulted in a decrease of the maximum temperature of hydrolysis. The pH, temperature, and the amount of enzyme added showed interactive effects on the observed rate of hydrolysis. No product or substrate inhibition was observed. Stirring did not effect the rate of hydrolysis. The oligosaccharide composition after hydrolysis (at a certain dextrose equivalent) did depend on the reaction temperature. The level of maltopentaose [15–24% [w/w]], a major product of starch hydrolysis by B. licheniformis α‐amylase, was influenced mostly by temperature. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 62: 348–357, 1999.

show abstract

Cation‐Activated Enzymes

Glusker

2005

Encyclopedia of Inorganic Chemistry

View full text Add to dashboard Cite

Cation‐activated enzymes are those that require a cation for maximal activity but which still have some activity in the absence of the cation, that is, the activating cation is not an essential part of the enzyme mechanism. The cations involved are generally metal or ammonium ions. The metal ions used are generally Na + , K + , Mg 2+ , or Ca 2+ , those that are abundant in nature. In the last 10 years, many crystal structures of cation‐activated enzymes have been determined and, in these studies, potassium is the most common activating cation. The geometry of binding and possible conclusions about this activity are the subject of this review. Chosen for description are thrombin (a sodium‐activated enzyme), pyruvate kinase, dialkylglycine decarboxylase, diol dehydrase, inosine monophosphate dehydrogenase, and tryptophanase (all potassium‐activated enzymes), and alkaline phosphatase (a magnesium‐activated enzyme). In some enzymes, the activating cation is near the active site, but in others it is distant. This implies that its function in these two possibilities involves the modification of the charge distribution in the reaction center or else stabilization of the enzyme conformation most suited to the reaction to be catalyzed. These studies provide information on one way in which nature controls enzyme activity, and hopefully further studies will help us learn more possibilities for utilizing these enzyme‐control strategies in medicine.

show abstract

Activation of Bacillus licheniformis α-amylase through a disorder→order transition of the substrate-binding site mediated by a calcium–sodium–calcium metal triad

Cited by 231 publications

References 42 publications

The influence of secretory-protein charge on late stages of secretion from the Gram-positive bacterium Bacillus subtilis

The influence of secretory-protein charge on late stages of secretion from the Gram-positive bacterium Bacillus subtilis

The effect of process conditions on the ?-amylolytic hydrolysis of amylopectin potato starch: An experimental design approach

Cation‐Activated Enzymes

Contact Info

Product

Resources

About