scholarly journals Mutations associated with pyrazinamide resistance in pncA of Mycobacterium tuberculosis complex organisms.

1997 ◽  
Vol 41 (3) ◽  
pp. 636-640 ◽  
Author(s):  
S Sreevatsan ◽  
X Pan ◽  
Y Zhang ◽  
B N Kreiswirth ◽  
J M Musser
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Mycobacterium Tuberculosis Complex ◽  
Tuberculosis Complex ◽  
Primary Amino Acid Sequence ◽  
Primary Amino ◽  
Nucleotide Insertions ◽  
Striking Contrast

A gene (pncA) with mutations associated with pyrazinamide resistance in Mycobacterium tuberculosis complex members was characterized in 67 pyrazinamide-resistant and 51 pyrazinamide-susceptible isolates recovered from diverse geographic localities and anatomic sites and typed by IS6110 profiling. All pyrazinamide-susceptible organisms had identical pncA alleles. In striking contrast, 72% of the 67 resistant organisms had pncA mutations that altered the primary amino acid sequence of pyrazinamidase. A total of 17 previously undescribed mutations were found, including upstream mutations, missense changes, nucleotide insertions and deletions, and termination mutations. The mutations were arrayed along virtually the entire length of the gene. These data are further evidence that most drug resistance in M. tuberculosis is due to simple mutations occurring in chromosomally encoded genes rather than to acquisition of resistance genes by horizontal transfer events.

scholarly journals Intracellular Retention of the Corticotrophin-releasing Hormone (CRH) Precursor Within COS-7 Cells

1998 ◽  
Vol 46 (10) ◽  
pp. 1193-1197 ◽  
Author(s):  
Marcelo J. Perone ◽  
Simon Windeatt ◽  
Ewan Morrison ◽  
Andy Shering ◽  
Peter Tomasec ◽  
...  
Keyword(s):  
Amino Acid ◽  
Golgi Apparatus ◽  
Amino Acid Sequence ◽  
Protein Secretion ◽  
Intracellular Trafficking ◽  
Secretory Pathway ◽  
Intracellular Localization ◽  
Primary Amino Acid Sequence ◽  
Releasing Hormone ◽  
Primary Amino

We investigated the intracellular localization of CRH in transiently transfected COS-7 cells expressing the full-length rat corticotropin-releasing hormone (CRH) precursor cDNA. CRH synthesized by transfected COS-7 cells is mainly stored intracellularly. In contrast, CHO-K1 cells expressing the same CRH precursor stored and released equal amounts of immunoreactive (IR)-CRH. Ultrastructural analysis revealed that CRH is stored in electron-dense aggregates in the RER of transiently transfected COS-7 cells and does not migrate into the Golgi apparatus. On the basis of the different intracellular localization, storage, and release of CRH in COS-7 and CHO-K1 cells, we hypothesize that the intracellular trafficking of CRH within the constitutive secretory pathway for protein secretion not only depends on its primary amino acid sequence but might also be influenced by intracellular conditions or factors.

scholarly journals Diversified lineages and drug-resistance profiles of clinical isolates of Mycobacterium tuberculosis complex in Malaysia

2019 ◽  
Vol 8 (4) ◽  
pp. 320
Author(s):  
MohdSalleh Zaki ◽  
MohdNur Noorizhab Fakhruzzaman ◽  
NorzulianaZainal Abidin ◽  
ZirwatulAdilah Aziz ◽  
WaiFeng Lim ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Mycobacterium Tuberculosis Complex ◽  
Clinical Isolates ◽  
Tuberculosis Complex

scholarly journals Amino acid sequence and the cellular location of the Na+-dependent d-glucose symporters (SGLT1) in the ovine enterocyte and the parotid acinar cell

1995 ◽  
Vol 312 (1) ◽  
pp. 293-300 ◽  
Author(s):  
P S Tarpey ◽  
I S Wood ◽  
S P Shirazi-Beechey ◽  
R B Beechey
Keyword(s):  
Plasma Membrane ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Amino Acid Sequences ◽  
Primary Amino Acid Sequence ◽  
Parotid Acinar Cells ◽  
Parotid Acinar Cell ◽  
Primary Amino

The Na(+)-dependent D-glucose symporter has been shown to be located on the basolateral domain of the plasma membrane of ovine parotid acinar cells. This is in contrast to the apical location of this transporter in the ovine enterocyte. The amino acid sequences of these two proteins have been determined. They are identical. The results indicated that the signals responsible for the differential targeting of these two proteins to the apical and the basal domains of the plasma membrane are not contained within the primary amino acid sequence.

CD156 (Human ADAM8): Expression, Primary Amino Acid Sequence, and Gene Location

Genomics ◽  
1997 ◽  
Vol 41 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Kazuhiro Yoshiyama ◽  
Yasunori Higuchi ◽  
Masashi Kataoka ◽  
Keiko Matsuura ◽  
Shunsuke Yamamoto
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Gene Location ◽  
Primary Amino Acid Sequence ◽  
Primary Amino

scholarly journals Drug Resistance of Mycobacterium tuberculosis Complex in a Rural Setting, Angola

2018 ◽  
Vol 24 (3) ◽  
pp. 569-572 ◽  
Author(s):  
Ariadna Rando-Segura ◽  
María Luisa Aznar ◽  
María Milagros Moreno ◽  
Mateu Espasa ◽  
Elena Sulleiro ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Mycobacterium Tuberculosis Complex ◽  
Rural Setting ◽  
Tuberculosis Complex

scholarly journals Drug Resistance of Mycobacterium tuberculosis Complex in a Rural Setting, Angola

2018 ◽  
Vol 24 (3) ◽  
pp. 569-572
Author(s):  
Ariadna Rando-Segura ◽  
María Luisa Aznar ◽  
María Milagros Moreno ◽  
Mateu Espasa ◽  
Elena Sulleiro ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Mycobacterium Tuberculosis Complex ◽  
Rural Setting ◽  
Tuberculosis Complex

scholarly journals New Delhi metallo-β-lactamase (NDM)

2015 ◽  
Vol 37 (3) ◽  
pp. 18-21
Author(s):  
Hao Yang ◽  
Michael W. Crowder
Keyword(s):  
Antibacterial Activity ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Substrate Preference ◽  
New Delhi ◽  
Primary Amino Acid Sequence ◽  
Substrate Specificities ◽  
Clinical Variants ◽  
Primary Amino ◽  
Multiple Variants

Metallo-β-lactamases (MBLs) are a class of Zn(II)-containing enzymes that hydrolyse the β-lactam bond in β-lactam-containing antibiotics, resulting in products that no longer exhibit antibacterial activity. Currently, there are 29 known MBLs (not including variants), and these enzymes have been classified on the basis of primary amino acid sequence and functionality into three or four classes (see www.mbled.uni-stuttgart.de for an updated MBL database)1. MBLs in classes B1 and B3 are known for their ability to hydrolyse all β-lactam antibiotics, except monobactams, including penicillins, carbapenems and cephalosporins. The class B2 enzymes exhibit a narrower substrate preference and preferentially hydrolyse carbapenems2. The most clinically important MBLs belong to class B1, which contains VIM (Verona integrinencoded MBLs), IMP (imipenemase) and NDM (New Delhi MBL), and all of these enzymes have multiple clinical variants (VIM-1—VIM-46, IMP-1—IMP-51, and NDM-1—NDM-16) (www.lahey.org/Studies/). The presence of multiple variants poses a challenge to identify clinical inhibitors because the variants often exhibit different substrate specificities and are affected differently by known non-clinical inhibitors3.

scholarly journals Organic Salts Based on Isoniazid Drug: Synthesis, Bioavailability and Cytotoxicity Studies

Pharmaceutics ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 952
Author(s):  
Filipa Santos ◽  
Luís C. Branco ◽  
Ana Rita C. Duarte
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Organic Cation ◽  
Mycobacterium Tuberculosis Complex ◽  
Tuberculosis Complex ◽  
Organic Salts ◽  
Cytotoxicity Studies ◽  
Drug Regimens ◽  
Drug Synthesis ◽  
Polymorphic Forms

Tuberculosis is one of the ten causes of morbidity and mortality worldwide caused by Mycobacterium tuberculosis complex. Some of the anti-tuberculosis drugs used in clinic studies, despite being effective for the treatment of tuberculosis, present serious adverse effects as well as poor bioavailability, stability, and drug-resistance problems. Thus, it is important to develop approaches that could provide shorter drug regimens, preventing drug resistance, toxicity of the antibiotics, and improve their bioavailability. Herein, we reported the use of organic salts based on the isoniazid drug, which can act as an organic cation combined with suitable organic anions such as alkylsulfonate-based (mesylate, R or S-Camphorsulfonate), carboxylate-based (glycolate, vanylate) and sacharinate. The synthesis, characterization, and cytotoxicity studies comparing with the original isoniazid drug have been performed. The possibility to explore dicationic salts seems promising in order to improve original bioavailability, and promote the elimination of polymorphic forms as well as higher stability, which are relevant characteristics that the pharmaceutical industry pursues.

Sign in / Sign up

Export Citation Format

Share Document