Inhibitors of the energy metabolism, such as sodium azide and valinomycin, render yeast cells completely resistant against the killing action of a number of cationic antimicrobial peptides, including the salivary antimicrobial peptide Histatin 5. In this study the Histatin 5-mediated killing of the opportunistic yeast Candida albicans was used as a model system to comprehensively investigate the molecular basis underlying this phenomenon. Using confocal and electron microscopy it was demonstrated that the energy poison azide reversibly blocked the entry of Histatin 5 at the level of the yeast cell wall. Azide treatment hardly induced depolarization of the yeast cell membrane potential, excluding it as a cause of the lowered sensitivity. In contrast, the diminished sensitivity to Histatin 5 of energy-depleted C. albicans was restored by increasing the fluidity of the membrane using the membrane fluidizer benzyl alcohol. Furthermore, rigidification of the membrane by incubation at low temperature or in the presence of the membrane rigidifier Me(2)SO increased the resistance against Histatin 5, while not affecting the energy charge of the cell. In line, azide induced alterations in the physical state of the interior of the lipid bilayer. These data demonstrate that changes in the physical state of the membrane underlie the increased resistance to antimicrobial peptides.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1074/jbc.M610555200 | DOI Listing |
ACS Biomater Sci Eng
January 2025
Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, P. R. China.
Bacterial biofilms, complex microbial communities encased in a protective extracellular matrix, pose a significant threat to public health due to their inherent antibiotic resistance. This review explores the potential of peptides, particularly antimicrobial peptides (AMPs), as innovative tools to combat biofilm-related infections. AMPs, characterized by their potent antimicrobial activity and tissue permeability, offer a promising approach to overcome the challenges posed by biofilms.
View Article and Find Full Text PDFExp Appl Acarol
January 2025
Group for Medical Entomology, Centre of Excellence for Food- and Vector-Borne Zoonoses, Institute for Medical Research, National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia.
Tick salivary proteins are crucial for efficient and successful tick feeding. Most of them are still uncharacterized, especially those involved in the formation of tick cement. Tick salivary protein PA107 is a putative cement protein, which is transcribed in salivary glands during the initial phase of tick feeding.
View Article and Find Full Text PDFArch Dermatol Res
January 2025
Dermatology and Venereology Department, Faculty of Medicine, Tanta University, Tanta, Egypt.
Vitiligo is a pigmentary disorder acquired and caused by the loss or destruction of melanocytes from the epidermis. There is strong proof that vitiligo is mainly an autoimmune disease. Cathelicidin (LL37), an antimicrobial polypeptide, is an important part of the innate immune system and has a role in different skin autoimmune diseases.
View Article and Find Full Text PDFBiochemistry
January 2025
Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa.
C-terminal amidation of antimicrobial peptides (AMPs) is a frequent minor modification used to improve antibacterial potency, commonly ascribed to increased positive charge, protection from proteases, and a stabilized secondary structure. Although the activity of AMPs is primarily associated with the ability to penetrate bacterial membranes, hitherto the effect of amidation on this interaction has not been understood in detail. Here, we show that amidation of the scorpion-derived membranolytic peptide AamAP1-Lys produces a potent analog with faster bactericidal activity, increased membrane permeabilization, and greater Gram-negative membrane penetration associated with greater conformational flexibility.
View Article and Find Full Text PDFACS Infect Dis
January 2025
Infectious Diseases Division, CSIR─Indian Institute of Integrative Medicine, Jammu 180001, India.
Tuberculosis (TB), a leading infectious disease caused by the pathogen , poses a significant treatment challenge due to its unique characteristics and resistance to existing drugs. The conventional treatment regimens, which are lengthy and involve multiple drugs, often result in poor patient adherence and subsequent drug resistance, particularly with multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains. This highlights the urgent need for novel anti-TB therapies and new drug targets.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!