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幫我翻譯英文MYROSINASE OF WASABI
要文意通暢不要翻譯機翻的!!謝謝了
MYROSINASE OF WASABI
Many of the properties of wasabi myrosinase have been
determined by Ohtsuru and Kawatani (1979). It is one
of the largest myrosinases yet described, having a mole-
cular weight of 580Kd compared to 120-150Kd for
mustard or 90 Kd for Aspergillus niger. It consists of 12
subunits as assessed by sodium dodecyl sulphate-poly-
acrylamide gel electrophoresis (SDS-PAGE). This large
molecular weight may contribute to the poor thermal
stability of this enzyme. Myrosinase is present in the
cells as a particle (insoluble) enzyme which is not readily
extracted by washing with buffer, even with Triton-X,
but requires sonication to release it.
The enzyme has an optimum pH of approximately 7,
at which it is also most stable. It shows maximum
activity at 37℃ over a 20-min period, but rapidly
becomes inactivated at temperatures above 30℃. It is
activated by a number of metal ions including Ca2+,
Co2+, Ni2+, K+, Zn2+ and Mg2+, weakly inhibited by
Fe3+ and strongly inhibited by both Cu2+ and Hg2+. It
is also activated by l-ascorbic acid but not by ascorbic
acid analogs nor by other reducing agents, except in the
presence of ascorbic acid. The optimum concentration
of ascorbic acid was around 2mM (Ohtsuru and
Kawatani, 1979). The fragility of the wasabi myrosinase
means that a wasabi powder containing active enzyme is
difficult to prepare. One solution to this problem is to
blend the wasabi powder with a crude myrosinase pre-
paration, or with powdered mustard, horseradish or
similar myrosinase-containing materials (Ebisawa et al.,
1988). Provided the myrosinase is reasonably pure, the
flavour of the powder should not be aected, but any
glucosinolates in the enzyme preparation may impart
additional flavours, such as a mustard, pepper or
horseradish flavour. Work conducted at Lincoln Uni-
versity shows that powdered horseradish may also impart
an unpleasant `turnip' flavour to any final product.
3 Answers
- 1 decade agoFavorite Answer
WASABI黑芥子酶 許多wasabi黑芥子酶物產是確定Ohtsuru和Kawatani (1979)。 它是一最大的黑芥子酶,描述,有痣cular重量580Kd與120-150Kd比較了為芥末或90黑麴霉的Kd。 包括12個亞單位如鈉十二烷基硫酸鹽多估計它丙烯酰胺膠凝體電泳法(SDS-PAGE)。 大這分子量也許造成恶劣的上升暖流這酵素的穩定。 黑芥子酶是存在細胞作為沒有通过洗滌欣然提取與緩衝,甚而與氚核X的微粒(不能溶解的)酵素,但是要求聲處理發布它。酵素有最宜酸碱度大约7,在哪些它最也是槽櫪。 它顯示最大值在迅速37℃的活動在20分鐘期間,但是变得撤消在30℃之上的溫度。 它是激活由一定數量的金屬離子包括Ca2+, Co2+, Ni2+、,微弱地被禁止的K+、Zn2+和Mg2+ Fe3+和強烈禁止由Cu2+和Hg2+。 它也激活被l抗壞血症的酸,但是不被抗坏血酸類似物亦不被其他脱氧剂,除了在抗坏血酸面前。 最宜的集中抗坏血酸是大约2mM (Ohtsuru和 kawatani 1979)。 wasabi黑芥子酶的脆弱意味着包含活躍酵素的wasabi粉末是难準備。 對這個問題的一種解答將與預備粗暴的黑芥子酶混和wasabi粉末 paration,或者用搽粉的芥末,辣根或相似的黑芥子酶包含的材料(等Ebisawa, 1988)。 假設黑芥子酶是合理地純淨的,粉末的味道不應該是 ected的,而是其中任一在酶制剂的葡萄糖基芥子油苷也許給予另外調味,例如芥末,胡椒或辣根味道。 工作被舉辦在林肯單 versity表示,搽粉的辣根也許也給予一令人不快的`turnip& #039; 對任何最终产品的味道。