Thermolysin crystal suspension

Mechanism of Crystal Growth of Protein Differential Scanning Calorimetry of Thermolysin Crystal Suspension... 

The thermal analysis by DSC was carried out for thermolysin crystal suspensions in which crystal growth was on progress. As a result, it was found that three ups of thermolysin differing in the thermal stability exist. Each group was assigned to monomers, oligomers, and crystals, respectively. The denaturation temperature of... 

The crystal suspension was filtered through a membrane filter of 0.45 yun (filtrate A). Part of the filtrate A was further filtered ti ugh an ultra filter (molecular mass cut off 100 kD) (filtrate B). The filtrate A included particles of thermolysin smaller than 0.45 im. The filtrate B mainly consisted of thermolysin molecules because the molecular mass of thermolysin is 34.6 kD. Both filtrates were analyzed by gel filtration lugh performance liquid chromatography (HPLC). In the analysis, the filtrates were adjust to pH 11.0 before use as sample solutions to dissolve the crystals which had precipitated in the filtrates after the filtration. 

The suspension of thermolysin crystal separately prepared in the glass tube was incubated at 85,90, and 95 °C for 1 h. The thermally treated suspension was observed by optical microscopy. 

Fig.2 DSC curves for suspensions of thermolysin crystal (initial concentration 3 m mL in water (initial supersaturation ratio 18.7)) differing in crystallization time, i.e. zero and 24 h. Solvent water (pH 7.0, 5 °C). Temperature scanning rate 90°C7h.

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