Identifikasi Karakter Siswa Menggunakan Metode K-Means (Studi Kasus Sdn 156 Pekanbaru)

Good character education can have a characteristic impact on students. each student has a different character. Various ways done by the school in character education based on kemendiknas, including State Elementary School 156 Pekanbaru. Problems that arise in the field is there is no method that can determine the character of the students so that the school's special teachers can not understand precisely the characters in the students. The lack of understanding of the character of the students makes the vision of the school mission has not been seen so that character education in SDN 156 Pekanbaru has not been right target. Therefore, it needs to be done grouping student character in SDN 156 Pekanbaru with the aim of school know character owned by students in school. The K-Means algorithm is used to classify the character of the students with the number of clusters as much as 2 using the six attributes of characters studied: Honest, disciplined, confident, caring, creative and responsible with 130 student data. The results of K-Means manual calculation with sample data 10 data from 130 data that is weak character (C1) amounted to 1 student and weak character of 9 students, this result is same with calculation executed by RapidMiner application. Test results with 130 data using RapidMiner resulted in the number of students with weak character 26 students with the average centroid (0.665) with caring and creative characters. While students who have strong character 104 students with average value of centroid (0.900) with honest character, discipline, confidence, and responsibility. The result of character grouping based on class cluster position in RapidMiner is grade 3 which has weak character (C1) 8 students from 35 students, grade 4 is 8 out of 24 students, 5th grade is 1 of 17 students and grade 6 is 9 of 46 students. While clusters with strong characters (C2) class 3 amounted to 27 students, grade 4 amounted to 24 students, class 5 amounted to 16 students, and grade 6 amounted to 37 students. From the results of this study is expected Strong characters can be developed by school continue to perform habits which involves the students so that the characters in the students can be seen while for the caring and creative characters so as not to be weak then the school always provide guidance to the students and give examples of good habits and activities that can be followed by students in school

Lipids modulate the conformational dynamics of a secondary multidrug transporter

Direct interactions with lipids have emerged as key determinants of the folding, structure and function of membrane proteins, but an understanding of how lipids modulate protein dynamics is still lacking. Here, we systematically explored the effects of lipids on the conformational dynamics of the proton-powered multidrug transporter LmrP from Lactococcus lactis, using the pattern of distances between spin-label pairs previously shown to report on alternating access of the protein. We uncovered, at the molecular level, how the lipid headgroups shape the conformational-energy landscape of the transporter. The model emerging from our data suggests a direct interaction between lipid headgroups and a conserved motif of charged residues that control the conformational equilibrium through an interplay of electrostatic interactions within the protein. Together, our data lay the foundation for a comprehensive model of secondary multidrug transport in lipid bilayers

A single active catalytic site is sufficient to promote transport in P-glycoprotein

P-glycoprotein (Pgp) is an ABC transporter responsible for the ATP-dependent efflux of chemotherapeutic compounds from multidrug resistant cancer cells. Better understanding of the molecular mechanism of Pgp-mediated transport could promote rational drug design to circumvent multidrug resistance. By measuring drug binding affinity and reactivity to a conformation-sensitive antibody we show here that nucleotide binding drives Pgp from a high to a low substrate-affinity state and this switch coincides with the flip from the inward- to the outward-facing conformation. Furthermore, the outward-facing conformation survives ATP hydrolysis: the post-hydrolytic complex is stabilized by vanadate, and the slow recovery from this state requires two functional catalytic sites. The catalytically inactive double Walker A mutant is stabilized in a high substrate affinity inward-open conformation, but mutants with one intact catalytic center preserve their ability to hydrolyze ATP and to promote drug transport, suggesting that the two catalytic sites are randomly recruited for ATP hydrolysis

Structure of the polycystic kidney disease TRP channel Polycystin-2 (PC2)

Mutations in either polycystin-1 (PC1 or PKD1) or polycystin-2 (PC2, PKD2 or TRPP1) cause autosomal-dominant polycystic kidney disease (ADPKD) through unknown mechanisms. Here we present the structure of human PC2 in a closed conformation, solved by electron cryomicroscopy at 4.2-Å resolution. The structure reveals a novel polycystin-specific 'tetragonal opening for polycystins' (TOP) domain tightly bound to the top of a classic transient receptor potential (TRP) channel structure. The TOP domain is formed from two extensions to the voltage-sensor-like domain (VSLD); it covers the channel's endoplasmic reticulum lumen or extracellular surface and encloses an upper vestibule, above the pore filter, without blocking the ion-conduction pathway. The TOP-domain fold is conserved among the polycystins, including the homologous channel-like region of PC1, and is the site of a cluster of ADPKD-associated missense variants. Extensive contacts among the TOP-domain subunits, the pore and the VSLD provide ample scope for regulation through physical and chemical stimuli

The structural basis of lipid scrambling and inactivation in the endoplasmic reticulum scramblase TMEM16K

Membranes in cells have defined distributions of lipids in each leaflet, controlled by lipid scramblases and flip/floppases. However, for some intracellular membranes such as the endoplasmic reticulum (ER) the scramblases have not been identified. Members of the TMEM16 family have either lipid scramblase or chloride channel activity. Although TMEM16K is widely distributed and associated with the neurological disorder autosomal recessive spinocerebellar ataxia type 10 (SCAR10), its location in cells, function and structure are largely uncharacterised. Here we show that TMEM16K is an ER-resident lipid scramblase with a requirement for short chain lipids and calcium for robust activity. Crystal structures of TMEM16K show a scramblase fold, with an open lipid transporting groove. Additional cryo-EM structures reveal extensive conformational changes from the cytoplasmic to the ER side of the membrane, giving a state with a closed lipid permeation pathway. Molecular dynamics simulations showed that the open-groove conformation is necessary for scramblase activity

GFP-Based expression screening of membrane proteins in insect cells using the baculovirus system

A key step in the production of recombinant membrane proteins for structural studies is the optimization of protein yield and quality. One commonly used approach is to fuse the protein to green fluorescent protein (GFP), enabling expression to be tracked without the need to purify the protein. Combining fusion to green fluorescent protein with the baculovirus expression system provides a useful platform for both screening and production of eukaryotic membrane proteins. In this chapter we describe our protocol for the expression screening of membrane proteins in insect cells using fusion to GFP as a reporter. We use both SDS-PAGE with in-gel fluorescence imaging and fluorescence-detection size-exclusion chromatography (FSEC) to screen for expression

GFP-Based Expression Screening of Membrane Proteins in Insect Cells Using the Baculovirus System.

A key step in the production of recombinant membrane proteins for structural studies is the optimization of protein yield and quality. One commonly used approach is to fuse the protein to green fluorescent protein (GFP), enabling expression to be tracked without the need to purify the protein. Combining fusion to green fluorescent protein with the baculovirus expression system provides a useful platform for both screening and production of eukaryotic membrane proteins. In this chapter we describe our protocol for the expression screening of membrane proteins in insect cells using fusion to GFP as a reporter. We use both SDS-PAGE with in-gel fluorescence imaging and fluorescence-detection size-exclusion chromatography (FSEC) to screen for expression