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Literature summary for 3.2.1.2 extracted from

  • Ma, Y.F.; Evans, D.E.; Logue, S.J.; Langridge, P.
    Mutations of barley beta-amylase that improve substrate-binding affinity and thermostability (2001), Mol. Genet. Genomics, 266, 345-352.
    View publication on PubMed
Search for more literature for 3.2.1.2

Application

Application Comment Organism
brewing beta-amylase allelic forms have different thermostability and kinetic properties, which critically influence their malting quality, production of barley varieties with better malting quality by genetic engineering Hordeum vulgare

Cloned(Commentary)

Cloned (Comment) Organism
two of the 3 allelic forms of beta-amylase Sd1 and Sd2L are cloned and sequenced Hordeum vulgare

Protein Variants

Protein Variants Comment Organism
D165E Sd2L mutant Hordeum vulgare
L347S Sd2L mutant, mutation increases the thermostability index T50 by 2.1°C by slowing thermal unfolding of enzyme during heating Hordeum vulgare
additional information Sd1 and Sd2L beta-amylase with a 46 amino acid deletion in the C-terminal tail Hordeum vulgare
R115C Sd2L mutant, mutation is responsible for the difference in the kinetic properties of the allelic forms Hordeum vulgare
V233A Sd2L and Sd1 mutant, mutation increases the thermostability index T50 of Sd2L by 1.9°C, mutation causes an acceleration of the refolding after heating Hordeum vulgare
V233A/L347S Sd2L double mutation resulting in exactly the same sequence as Sd2H beta-amylase, mutation increases the thermostability index T50 of Sd2L by 4°C Hordeum vulgare
V430A Sd2L mutant Hordeum vulgare

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
additional information
-
 additional information the 3 allelic forms of beta-amylase Sd1, Sd2H and Sd2L exhibit different kinetic properties, an R115C mutation is responsible for this difference Hordeum vulgare
0.00317
-
 starch pH 5, 40°C, soluble starch, V233A mutant of Sd1 Hordeum vulgare
0.0033
-
 starch pH 5, 40°C, soluble starch, wild-type Sd1 Hordeum vulgare
0.0036
-
 starch pH 5, 40°C, soluble starch, R115C mutant of Sd2L Hordeum vulgare
0.00825
-
 starch pH 5, 40°C, soluble starch, V233A mutant of Sd2L Hordeum vulgare
0.0083
-
 starch pH 5, 40°C, soluble starch, wild-type Sd2H and V233A/L347S double mutant of Sd2L Hordeum vulgare
0.00831
-
 starch pH 5, 40°C, soluble starch, wild-type Sd2L Hordeum vulgare
0.00834
-
 starch pH 5, 40°C, soluble starch, L347S mutant of Sd2L Hordeum vulgare
0.00838
-
 starch pH 5, 40°C, soluble starch, V430A mutant of Sd2L Hordeum vulgare
0.00856
-
 starch pH 5, 40°C, soluble starch, D165E mutant of Sd2L Hordeum vulgare

Organism

Organism UniProt Comment Textmining
Hordeum vulgare
-
 3 allelic forms: Sd1, Sd2H and Sd2L, amino acid differences between the 3 forms, wild barley subsp. spontaneum NPGS PI29689, var. Haruna Nijo, Adorra and Hiproly
-

Purification (Commentary)

Purification (Comment) Organism
recombinant mutant enzymes Hordeum vulgare

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
p-nitrophenylmaltopentaoside + H2O catalyzes the release of maltose Hordeum vulgare ?
-
 ?
starch + H2O catalyzes the release of maltose from soluble starch, three-dimensional structures of Sd2L and V233A mutant of Sd1 Hordeum vulgare ?
-
 ?

Synonyms

Synonyms Comment Organism
Sd1 one of three allelic forms of Hordeum beta-amylase Hordeum vulgare
Sd2H one of three allelic forms of Hordeum beta-amylase Hordeum vulgare
Sd2L one of three allelic forms of Hordeum beta-amylase Hordeum vulgare

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
40
-
 assay at Hordeum vulgare

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
additional information
-
 the 3 allelic forms of beta-amylase Sd1, Sd2H and Sd2L exhibit different thermostability, due to two amino acid substitutions, V233A and L347S, which increase the thermostability index T50 of Sd2L by 1.9°C and 2.1°C, respectively Hordeum vulgare
55.2
-
 T50 value for wild-type Sd2L and its D165E mutant Hordeum vulgare
55.3
-
 T50 value for R115C and V430A mutants of Sd2L Hordeum vulgare
57.1
-
 T50 value for V233A mutant of Sd2L Hordeum vulgare
57.3
-
 T50 value for wild-type Sd1 and L347S mutant of Sd2L Hordeum vulgare
59.2
-
 T50 value for wild-type Sd2H and V233A/L347S double mutant of Sd2L Hordeum vulgare
59.4
-
 T50 value for V233A mutant of Sd1 Hordeum vulgare

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
299
-
 starch pH 5, 40°C, soluble starch, wild-type Sd2L Hordeum vulgare
305
-
 starch pH 5, 40°C, soluble starch, wild-type Sd1 Hordeum vulgare
308
-
 starch pH 5, 40°C, soluble starch, wild-type Sd2H and V233A/L347S double mutant of Sd2L Hordeum vulgare
309
-
 starch pH 5, 40°C, soluble starch, L347S and R115C mutants of Sd2L Hordeum vulgare
314
-
 starch pH 5, 40°C, soluble starch, V233A mutant of Sd1 Hordeum vulgare
315
-
 starch pH 5, 40°C, soluble starch, V233A mutant of Sd2L Hordeum vulgare
319
-
 starch pH 5, 40°C, soluble starch, D165E and V430A mutants of Sd2L Hordeum vulgare

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
5
-
 assay at, starch as substrate Hordeum vulgare
6.2
-
 assay at, p-nitrophenylmaltopentaoside as substrate Hordeum vulgare