[多酚类抗氧化剂能有效保护脲酶免受超声空化作用导致的失活]

[Polyphenolic antioxidants efficiently protect urease from inactivation by ultrasonic cavitation].

作者信息

Metelitsa D I, Tarun E I, Losev Iu P

机构信息

Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, 220141 Belarus.

出版信息

Prikl Biokhim Mikrobiol. 2002 Nov-Dec;38(6):595-603.

PMID:12449786

Abstract

Inactivation of urease (25 nM) in aqueous solutions (pH 5.0-6.0) treated with low-frequency ultrasound (LFUS; 27 kHz, 60 Wt/cm2, 36-56 degrees C) or high-frequency ultrasound (HFUS; 2.64 MHz, 1 Wt/cm2, 36 or 56 degrees C) has been characterized quantitatively, using first-order rate constants: kin, aggregate inactivation; kin*, thermal inactivation; and kin* (US), ultrasonic inactivation. Within the range from 1 nM to 10 microM, propyl gallate (PG) decreases approximately threefold the rate of LFUS-induced inactivation of urease (56 degrees C), whereas resorcinol poly-2-disulfide prevents this process at 1 nM or higher concentrations. PG completely inhibits HFUS-induced inactivation of urease at 1 nM (36 degrees C) or 10 nM (56 degrees C). At 0.2-10 microM, human serum albumin (HSA) increases the resistance of urease (at 56 degrees C) treated with HFUS to temperature- and cavitation-induced inactivation. Complexes of gallic acid polydisulfide (GAPDS) with HSA (GAPDS-HSA), formed by conjugation of 1.0 nM PGDS with 0.33 nM HSA, prevent HFUS-induced urease inactivation (56 degrees C).

摘要

采用一级速率常数对脲酶（25 nM）在低频超声（LFUS；27 kHz，60 Wt/cm²，36 - 56℃）或高频超声（HFUS；2.64 MHz，1 Wt/cm²，36或56℃）处理的水溶液（pH 5.0 - 6.0）中的失活情况进行了定量表征：kin为聚集失活；kin为热失活；kin（US）为超声失活。在1 nM至10 μM范围内，没食子酸丙酯（PG）使LFUS诱导的脲酶失活速率（56℃）降低约三倍，而间苯二酚聚-2-二硫化物在1 nM或更高浓度时可阻止该过程。PG在1 nM（36℃）或10 nM（56℃）时完全抑制HFUS诱导的脲酶失活。在0.2 - 10 μM时，人血清白蛋白（HSA）增加了HFUS处理的脲酶（56℃）对温度和空化诱导失活的抗性。由1.0 nM PGDS与0.33 nM HSA共轭形成的没食子酸聚二硫化物（GAPDS）与HSA的复合物（GAPDS - HSA）可阻止HFUS诱导的脲酶失活（56℃）。