Dehydration of main-chain amides in the final folding step of single-chain monellin revealed by time-resolved infrared spectroscopy

Kinetic IR spectroscopy was used to reveal β-sheet formation and water expulsion in the folding of single-chain monellin (SMN) composed of a five-stranded β-sheet and an α-helix. The time-resolved IR spectra between 100 μs and 10 s were analyzed based on two consecutive intermediates, I1 and I2, appearing within 100 μs and with a time constant of ≈100 ms, respectively. The initial unfolded state showed broad amide I′ corresponded to a fluctuating conformation. In contrast, I1 possessed a feature at 1,636 cm−1 for solvated helix and weak features assignable to turns, demonstrating the rapid formation of helix and turns. I2 possessed a line for solvated helix at 1,637 cm−1 and major and minor lines for β-sheet at 1,625 and 1,680 cm−1, respectively. The splitting of the major and minor lines is smaller than that of the native state, implying an incomplete formation of the β-sheet. Furthermore, both major and minor lines demonstrated a low-frequency shift compared to those of the native state, which was interpreted to be caused by hydration of the C=O group in the β-sheet. Together with the identification of solvated helix, the core domain of I2 was interpreted as being hydrated. Finally, slow conversion of the water-penetrated core of I2 to the dehydrated core of the native state was observed. We propose that both the expulsion of water, hydrogen-bonded to main-chain amides, and the completion of the secondary structure formation contribute to the energetic barrier of the rate-limiting step in SMN folding

Preparation of α-mannoside hydrogel and electrical detection of saccharide-protein interactions using the smart gel-modified gate field effect transistor

The purpose of this study was to detect saccharide-protein interaction capitalizing on the gel-modified field effect transistor [FET]. A lectin-sensitive polymer gel that undergoes volume changes in response to the formation of molecular complex between 'pendant' carbohydrate and a 'target' lectin concanavalin A [Con A] was synthesized. It was revealed that direction and magnitude of the gel response (swelling or deswelling) could be readily designed depending on composition and network density of the gel. The Con A-sensitive polymer gel has shown the ability to transduce the detection of saccharide-protein interactions into electrical signals for FET

RESULTS OF EATON AND LITTLER'S LIGAMENT RECONSTRUCTION FOR INSTABILITY OF THE FIRST CARPOMETACARPAL JOINT

This study presents the cases of Eaton and Littler's ligament reconstruction for the treatment of instability of lst CM joint resulting from early stage osteoarthritis (Group OA), trauma (Group T), and a part of generalized joint laxity (Group GJL) in 21 joints of 20 cases. Omitting six cases with less than one year follow-up, 15 joints in 14 cases were analyzed. Clinically, hypermobility pain was improved in all joints. However, eight out of 14 patients felt their joints stretched, but still had the normal range of motion. Grip power and pinch power was significantly improved (P＜0.01, P＜0.05). Comparing each group, only Group T revealed a significant difference between preoperative and postoper- ative grip power (P＜0.01). In increase of grip power, Group T were more significantly improved than Group OA (P＜0.01) and Group GJL (P＜0.05). Radiographically, postoper- ative stages of 4 joints in 4 cases out of 8 cases which felt stretched progressed from their preoperative stages. We assumed that the newly reconstructed ligament may be strong enough to maintain the stability of 1st CM joint and ligament reconstruction is most effective in treating post-traumatic instability

RESULTS OF EATON AND LITTLER'S LIGAMENT RECONSTRUCTION FOR INSTABILITY OF THE FIRST CARPOMETACARPAL JOINT

This study presents the cases of Eaton and Littler's ligament reconstruction for the treatment of instability of lst CM joint resulting from early stage osteoarthritis (Group OA), trauma (Group T), and a part of generalized joint laxity (Group GJL) in 21 joints of 20 cases. Omitting six cases with less than one year follow-up, 15 joints in 14 cases were analyzed. Clinically, hypermobility pain was improved in all joints. However, eight out of 14 patients felt their joints stretched, but still had the normal range of motion. Grip power and pinch power was significantly improved (P＜0.01, P＜0.05). Comparing each group, only Group T revealed a significant difference between preoperative and postoper- ative grip power (P＜0.01). In increase of grip power, Group T were more significantly improved than Group OA (P＜0.01) and Group GJL (P＜0.05). Radiographically, postoper- ative stages of 4 joints in 4 cases out of 8 cases which felt stretched progressed from their preoperative stages. We assumed that the newly reconstructed ligament may be strong enough to maintain the stability of 1st CM joint and ligament reconstruction is most effective in treating post-traumatic instability