targeting-cysteine-thiols-for-vitro-site-specific-glycosylation

Targeting Cysteine Thiols for <em>in Vitro</em> Site-specific Glycosylation of Recombinant Proteins

Stromal interaction molecule-1 (STIM1) is a type-I transmembrane protein located on the endoplasmic reticulum (ER) and plasma membranes (PM). ER-resident ...

University of Western Ontario

There have been many efforts to develop efficient vaccines for the control of porcine reproductive and respiratory syndrome virus (PRRSV). Although inactivated PRRSV vaccines are preferred for their safety, they are weak at inducing humoral immune responses and controlling field PRRSV infection, especially when heterologous viruses are involved.

The assessment of efficacy of porcine reproductive respiratory syndrome virus inactivated vaccine based on the viral quantity and inactivation methods.

To compare the effects of lumbar stabilization exercises and lumbar dynamic strengthening exercises on the maximal isometric strength of the lumbar extensors, pain severity and functional disability in patients with chronic low back pain (LBP).

Effect of lumbar stabilization and dynamic lumbar strengthening exercises in patients with chronic low back pain.

In order to prevent fatty acid deficiency and to supply enough energy, intravenous fat emulsion is necessary for parenteral nutrition in preterm neonates. However, parenteral administration of intravenous fat emulsion can induce lipid intolerance. The purpose of this study was to analyze risk factors for lipid intolerance in very low birth weight infants. This retrospective study included 80 preterm neonates whose birth weight was less than 1,500 g. Subjects were divided into 2 categories: those with a serum triglyceride level of ≥ 200 mg/dl (n = 33, 41%) and those with a serum triglyceride level of < 200 mg/dl (n = 47, 59%). We conducted logistic regression analysis using variables which were significant in univariate analysis. All statistical analyses were processed in SPSS version 19.0. Four risk factors for lipid intolerance were obtained through analysis of the electronic medical record. Lipid intolerance occurred more frequently in neonates with sepsis; those with a birth weight less than 1,000 g; those who was administered intravenous fat emulsion more than 2.6 g/kg/day; and those whose gestational age was less than 28 weeks. It is suggested that serum triglyceride levels should be closely monitored to prevent lipid intolerance in preterm neonates with the aforementioned characteristics.

Analysis of risk factors for lipid intolerance of intravenous fat emulsion in very low birth weight infants.

A reply to the questions regarding to the article 'effect of lumbar stabilization and dynamic lumbar strengthening exercises in patients with chronic low back pain'.

A major intracellular calcium (Ca(2+)) uptake pathway in both excitable and non-excitable eukaryotic cells is store-operated Ca(2+) entry (SOCE). SOCE is the process by which endoplasmic reticulum (ER)-stored Ca(2+) depletion leads to activation of plasma membrane Ca(2+) channels to provide a sustained increase in cytosolic Ca(2+) levels that mediate a plethora of physiological processes ranging from the immune response to platelet aggregation. Stromal interaction molecule-1 (STIM1) is the principal regulator of SOCE and responds to changes in ER stored Ca(2+) through luminal sensing machinery composed of EF-hand and SAM domains (EFSAM). The EFSAM domain can undergo N-glycosylation at Asn131 and Asn171 sites; however, the precise role of EFSAM N-glycosylation in the Ca(2+) sensing mechanism of STIM1 is unclear. By establishing a site-specific chemical approach to covalently linking glucose to EFSAM and examining α-helicity, thermal stability, three dimensional atomic-resolution structure, Ca(2+) binding affinity and oligomerization, we show that N-glycosylation of the EFSAM domain enhances the properties that promote STIM1 activation. This augmentation occurs through changes in structure localized near the Asn131 and Asn171 sites that together permeate through the protein core and lead to decreased Ca(2+) binding affinity, reduced stability and enhanced oligomerization. Congruently, Ca(2+) influx via SOCE in HEK293 cells co-expressing Orai1 and STIM1 was diminished when N-glycosylation was blocked by introducing Asn131Gln and Asn171Gln mutations. Collectively, our data suggests that N-glycosylation enhances the EFSAM destabilization-coupled oligomerization in response to ER Ca(2+) depletion thereby augmenting the role of STIM1 as a robust ON/OFF regulator of SOCE. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.

Structural perturbations induced by Asn131 and Asn171 glycosylation converge within the EFSAM core and enhance stromal interaction molecule-1 mediated store operated calcium entry.

Yoo Jung Choi

Department of Physiology and Pharmacology,
Schulich School of Medicine and Dentistry,
Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry

University of Western Ontario

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Yoo Jung Choi

Department of Physiology and Pharmacology,Schulich School of Medicine and Dentistry,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry

University of Western Ontario

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Department of Physiology and Pharmacology,
Schulich School of Medicine and Dentistry,
Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry