Allergenicity and Physicochemical Characterization of House Dust Mite Derived Amylase

Abstract

The enzyme amylase was shown to be present in extracts prepared from both house dust and spent growth medium used in the culture of the mite Dermatophagoides pteronyssinus. In dust, it was shown to correlate with both mite counts and concentrations of the faecally derived mite allergen, Der p I. Mite amylase was isolated from the culture medium and shown to be a single chain protein with a molecular weight of 56,000. The enzyme contained free sulphydryl groups and had the N-terminal sequence, KYXNPHFIGX-RSVITXLME. It was found to be an allergen using sera from adults (46% positive) and children (25%) who were mite allergic. The expression of allergenicity was dependent on the integrity of intra-chain disulphide bonds.

Enzymatic activity and immunoreactivity of Aca s 4, an alpha-amylase allergen from the storage mite Acarus siro

“…The pH profile (Figure 4a) shows that the enzyme functions in the slightly acidic to neutral range, with a maximum at pH ~6.5, which is in accordance with the pH optimum of α-amylase activity measured with the whole body extract of A. siro [17]. A similar pH optimum was also reported for the purified Der p 4 [14]. We tested the modulation of the Aca s 4 activity by chloride ions, which are general activators of animal α-amylases [18,19].…”

“…Group 4 allergens have been investigated in house dust mites such as Dermatophagoides pteronyssinus, Euroglyphus maynei , and Blomia tropicalis , and their sequences have been determined [12-14]. The biochemical properties of Der p 4 were analyzed in detail, including its interaction with major cereal flour allergens that act as α-amylase inhibitors [14,15].…”

“…Group 4 allergens have been investigated in house dust mites such as Dermatophagoides pteronyssinus, Euroglyphus maynei , and Blomia tropicalis , and their sequences have been determined [12-14]. The biochemical properties of Der p 4 were analyzed in detail, including its interaction with major cereal flour allergens that act as α-amylase inhibitors [14,15]. The IgE-binding activity of group 4 allergens has been demonstrated for ~30% of allergic subjects in Western populations and China [12-14]; these allergens may also be the major contributor to the serum activity, as found in an Australian Aboriginal community [16].…”

“…The biochemical properties of Der p 4 were analyzed in detail, including its interaction with major cereal flour allergens that act as α-amylase inhibitors [14,15]. The IgE-binding activity of group 4 allergens has been demonstrated for ~30% of allergic subjects in Western populations and China [12-14]; these allergens may also be the major contributor to the serum activity, as found in an Australian Aboriginal community [16]. In this work, we analyze native Aca s 4 from A. siro , the first α-amylase allergen to be isolated from storage mites.…”

Environmental assessment and exposure control of dust mites: a practice parameter

“…In 1 study, sera from 25% of mite-allergic children and 46% of mite-allergic adults contained specific IgE to this allergen and directly correlated with concentrations of total mite-specific IgE. 334,335 Complement DNA clones of Der p 4 and Eur m 4 were sequenced and were found to code for 496 amino acid mature proteins with highly conserved residues that are important for the function of α-amylase. Der p 4 and Eur m 4 were 90% identical and were 50% identical to insect and mammalian α-amylases.…”