title: Characteristics of surface layer proteins from two new and native strains of Lactobacillus brevis.
abstract: In this work, some important characteristics of surface layer (S-layer) proteins extracted from two new and native Lactobacillus strains, L.brevis KM3 and L.brevis KM7, were investigated. The presence of S-layer on the external surface of L.brevis KM3 was displayed by thin sectioning and negative staining. SDS-PAGE analysis were shown same dominant protein bands approximately around 48kDa for both S-layer proteins. Moreover, the S-layer reappeared when LiCl treated cells were allowed to grow again. Protein secondary structure and thermal behavior were evaluated by using circular dichroism (CD) and differential scanning calorimetry (DSC), respectively. Both S-layer proteins had high content of β-sheet and low amount of α-helix. The thermograms of lyophilized S-layer proteins of L.brevis KM3 and L.brevis KM7 showed one transition peak at 67.9°C and 59.14°C, respectively. To determine monodispersity of extracted S-layer proteins, dynamic light scattering (DLS) was used. The results indicated that the main population of S-layer molecules in two tested lactobacillus strains were composed of monomer with an expected diameter close to 10nm. Furthermore, Zeta potential measurements were showed positive potential for both S-layer proteins, as expected. Our results could be used as the basis for biotechnological applications of these two new S-layer proteins.
authors.affiliation: Department of Microbiology, Faculty of Biological sciences, Alzahra University, Tehran, Iran. Electronic address: emobarak110@gmail.com.
authors.forename: Elahe
authors.initials: E
authors.lastname: Mobarak Qamsari
authors.affiliation: Department of Microbiology, Faculty of Biological sciences, Alzahra University, Tehran, Iran. Electronic address: rkasra@yahoo.com.
authors.forename: Rouha
authors.initials: R
authors.lastname: Kasra Kermanshahi
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: m-erfan@sbmu.ac.ir.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Erfan
authors.affiliation: Department of Biotechnology, Faculty of Biological sciences, Alzahra University, Tehran, Iran. Electronic address: pghadam@alzahra.ac.ir.
authors.forename: Parinaz
authors.initials: P
authors.lastname: Ghadam
authors.affiliation: Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Iran. Electronic address: ssardari@hotmail.com.
authors.forename: Soroush
authors.initials: S
authors.lastname: Sardari
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Lorestan University of Medical Sciences, Khorramabad, Iran. Electronic address: Nedaeslami77@yahoo.com.
authors.forename: Neda
authors.initials: N
authors.lastname: Eslami
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D002473:Cell Wall / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel; D005612:Freeze Drying; D015870:Gene Expression; D052196:Levilactobacillus brevis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D008867:Microtomy; D017433:Protein Structure, Secondary; D013194:Staining and Labeling
chemical_list: D001426:Bacterial Proteins; D008562:Membrane Glycoproteins; C055764:S-layer proteins
keywords: Lactobacillus brevis; Monodispersity; Secondary structure; Surface layer proteins; Thermal behavior; Zeta potential