Thermostated cell holder

Peptide synthesis was performed on an ABI 433 automatic peptide synthesizer using Fmoc solid phase peptide synthesis (SPPS). HPLC analysis were performed with a Shimadzu LC-10ADvp equipped with an SPDM10Avp diode-array detector.
Mass spectra were acquired on a MALDI-TOF Voyager PerSeptive BioSystem.
UV-vis spectra were recorded on a Cary Varian 50 Spectrophotometer, equipped with a thermostated cell compartment (Varian, Palo Alto, CA, USA);CD analysis were performed using a J-815 spectropolarimeter equipped with a thermostated cell holder (JASCO, Easton, MD, USA).
NMR experiments were acquired at 298 K on a Varian Inova spectrometer, operating at 500 MHz.

Circular dichroism (CD) measurements were recorded on a Jasco model J-1500 spectropolarimeter equipped with a thermostated cell holder (JASCO, Tokyo, Japan). Experiments were performed in a quartz cell with a 5 mm path length over the range of 200–260 nm at various temperatures, pH and different concentrations of metal ions. During CD spectroscopy analysis, respective purified erythrose reductase (0.1 mg/mL) was resuspended in the corresponding buffer (pH 2.5–9.0) and analyzed at 28 °C. Next, the spectra were acquired at pH 3.0 and pH 7.5 with different temperatures (10–53 °C), respectively. CD spectra were collected with a data pitch of 0.1 nm, bandwidth of 2.0 nm and scanning speed of 50 nm/min. The spectra represent the average of 6–9 scans, and data were analyzed using the K2D3 method. The K2D3 web server is an online tool used to assess the secondary structural elements in the form of α-helices and β-strands from far-UV CD spectra ranging from 200 to 240 nm [33 (link)].