Genetic engineering now enables generation of artificially modified antibodies having higher diagnostic utilities. The authors
developed single-chain Fv fragments (scFvs) against cortisol with >55-fold
improved affinity (Ka, 2.0-2.2 ´ 1010
M-1) by inserting additional amino acid(s) site-directedly
into the framework region 1 of the VH domain. These scFvs were fused
with NanoLuc luciferase for the use in an enzyme-linked immunosorbent assay
(ELISA) system. The resulting luminescent
ELISAs generated dose-response curves with >150-fold higher sensitivity than
the colorimetric ELISAs using the scFv without insertion and >8,000-fold
higher sensitivity than the ELISA using the mouse antibody from which the scFvs
were derived.
E. coli is
often employed for the cost-effective production of large quantities of recombinant
proteins. Conventionally, it is believed that post-translational modifications,
including glycosylation, do not transpire during protein expression in E.
coli. However, in the course of preparing recombinant galectin-2 protein
using E. coli, the authors discovered that phosphogluconoylation of Lys
residues and mistranslation of termination codons occurred. The authors have
elucidated strategies to mitigate these occurrences, proposing the addition of
tags, substitution of Lys residues, and modification of termination codons. These
methods offer valuable means to prevent undesired modifications, ensuring the production
of homogeneous recombinant proteins in E. coli.
The authors focused on cell-penetrating
peptides (CPPs) as penetration enhancers for ocular drug delivery. This study suggested
that the CPPs evaluated in this study can be penetration enhancers based on in
vitro intracellular uptake using a reconstructed human corneal epithelial
model. The CPPs could enhance the penetration of drug molecules into the cornea
in cases of coexistence as well as conjugation between CPPs and drug molecules.
The result of surface plasmon resonance showed that the electrostatic
interaction plays an important role. The authors expect that this fundamental
information in this article will support the development of new penetration
enhancers in eye drop formulations for ocular drug delivery.
Inflammation is responsible for the development of
various kidney diseases. Plasminogen activator
inhibitor-1 (PAI-1) is
involved in the
pathogenesis of inflammatory kidney injury; however, the regulatory mechanism
of PAI-1 in injured kidneys remains unclear. The authors
found that PAI-1 expression was increased in endothelial cells after
lipopolysaccharide (LPS, an inflammation inducer) treatment, and
pharmacological inhibition of PAI-1 reduced LPS-induced kidney injury.
Moreover, IL-6 exacerbated kidney injury concomitant with increased PAI-1
expression, and Arid5a deficiency partially suppressed the expression of IL-6
and PAI-1 in the kidneys after LPS treatment. These findings indicate that the
Arid5a/IL-6/PAI-1 signaling is involved in LPS-induced kidney injury.
Hericium
erinaceus
secretes an acidic ribonuclease (RNase) He1 belonged to RNase T1 family. The authors
decided on the structure of He1 apo form and He1/guanosine complex. The
mechanism of acidification of optimal pH in He1 was, in neutral environment, to
form the hydrogen bond between Asp 31 on α1β3- loop and His 34 (catalytic
residue), and repulsive each other Glu 92 and Asp 93 on β6,7- loop. Structure
comparison of He1 with other acidic RNases, Ms and U2, suggested that the
acidic residues on α1β3- and β6,7- loop may contribute to the acidification of
optimal pH in Ms and U2.