It has been previously demonstrated that laccases exhibit great potential for use in several industrial and environmental applications. In this paper, two laccase isoenzyme genes, lccB and lccC, were cloned and expressed in Pichia pastoris GS115. The sequence analysis indicated that the lccB and lccC genes consisted of 1,563 and 1,584 bp, and their open reading frames encoded 520 and 527 amino acids, respectively. They had 72.7% degree of identity in nucleotides and 86.7% in amino acids. The expression levels of LccB and LccC were up to 32,479 and 34,231 U/l, respectively. The recombinant laccases were purified by ultrafiltration and (NH4)2SO4 precipitation, showing a single band on SDS-PAGE, which had a molecular mass of 58 kDa. The optimal pH and temperature for LccB were 2.0 and 55°C with 2,2'-azino-bis-[3-ethylbenzthiazolinesulfonic acid (ABTS) as a substrate, whereas LccC exhibited optimal pH and temperature at 3.0 and 60°C. The apparent kinetic parameters of LccB were 0.43 mM for ABTS with a Vmax value of 51.28 U/mg, and the Km and Vmax values for LccC were 0.29 mM and 62.89 U/mg. The recombinant laccases were able to decolorize five types of dyes. Acid Violet 43 (100 g/ml) was completely decolorized by LccB or LccC (2 U/ml), and the decolorization of Reactive Blue KN-R (100 g/ml) was 91.6% by LccC (2 U/ml). Thus, the study characterizes useful laccase isoenzymes from T. versicolor that have the capability of being incorporated into the treatment of similar azo and anthraquinone dyes from dyeing industries.
An anti-CD30 antibody-drug conjugate incorporating the antimitotic agent DM1 and a stable SMCC linker, anti-CD30-MCC-DM1, was generated as a new antitumor drug candidate for CD30-positive hematological malignancies. Here, the in vitro and in vivo pharmacologic activities of anti-CD30-MCC-DM1 (also known as F0002-ADC) were evaluated and compared with ADCETRIS (brentuximab vedotin). Pharmacokinetics (PK) and the safety profiles in cynomolgus monkeys were assessed. Anti-CD30-MCC-DM1 was effective in in vitro cell death assays using CD30-positive lymphoma cell lines. We studied the properties of anti-CD30-MCC-DM1, including binding, internalization, drug release and actions. Unlike ADCETRIS, anti-CD30-MCC-DM1 did not cause a bystander effect in this study. In vivo, anti-CD30-MCC-DM1 was found to be capable of inducing tumor regression in subcutaneous inoculation of Karpas 299 (anaplastic large cell lymphoma), HH (cutaneous T-cell lymphoma) and L428 (Hodgkin’s disease) cell models. The half-lives of 4 mg/kg and 12 mg/kg anti-CD30-MCC-DM1 were about 5 days in cynomolgus monkeys, and the tolerated dose was 30 mg/kg in non-human primates, supporting the tolerance of anti-CD30-MCC-DM1 in humans. These results suggest that anti-CD30-MCC-DM1 presents efficacy, safety and PK profiles that support its use as a valuable treatment for CD30-positive hematological malignancies.
Indoor acoustic environment has become a critical factor in architectural design, and some researchers argued that the reactions from people of varied age, gender, etc. to indoor noise should be considered. While the office staff along metro lines get used to frequent metro noise, their metro noise perceptions, which are supposed to be different from non-office staff, need to be clearly examined. Based on on-site physical measurements and questionnaire surveys, this study aims to analyze the multi-dimensional perceptions (annoyance, dissatisfaction and unpleasantness) of office staff and non-office staff about metro noise in the underground commercial spaces of a high-rise building. The results indicate that due to lower adaptability and tolerance to metro noise, the non-office staff were more sensitive to the change of metro noise than the office staff, and compared with the office staff, the non-office staff expressed obviously more intense multi-dimensional negative moods under the same metro noise environments. Furthermore, for the non-office staff, their annoyance and dissatisfaction ratings due to metro noise correlated well with A-weighted equivalent sound pressure level (LAeq) and maximum A sound pressure level (LAFmax). Among the psychoacoustic measures, loudness and sharpness mainly influenced their annoyance and dissatisfaction perceptions.
A thermostable and
organic solvent-tolerant bacterial laccase from
Bacillus
pumilus
ARA has been expressed heterologously
and characterized, which shows potential decolorization capacity to
various types of industrial synthetic dyes. The optimal temperature
and pH were 85 °C and 3.5, respectively, while the purified recombinant
laccase B.P.Lacc was stable under 55–75 °C and pH 5.0–8.0
conditions. The apparent kinetic parameters
K
m
and
V
max
of B.P.Lacc for ABTS
as the substrate were 0.33 mM and 32.4 U/mg, respectively. Ethanol
(1%, v/v) and methanol (2%, v/v) could stimulate the enzyme activity.
The recombinant laccase retained over 95% of its initial activity
in 10% (v/v) methanol. The optimal expression conditions for the laccase
production of B.P.Lacc in LB medium were obtained: induction temperature
of 25 °C, 0.4 mM Cu
2+
, and 1.0 mM IPTG added into
the culture. After 5 h, the final laccase production was 1283 U/mL.
Moreover, the laccase activity increased to 4822 U/mL after follow-up
2 h stationary cultivation, with about a 3.76-fold increase. The purified
B.P.Lacc was able to efficiently decolorize synthetic dyes combined
with mediators. Adding 1.0 mM ABTS, more than 90% of BRRB was decolorized
by the enzyme, whether at pH 4.0 or pH 7.9. The outstanding enzymatic
properties suggested that B.P.Lacc may be suitable for a wide application
in future biodegradation fields.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.