European Journal of Mass Spectrometry - Abstract of Letter: Lanthanum-calcium-manganate (La0.67Ca0.33MnO3) nanoparticle assisted affinity probes for MALDI MS analysis of proteins

Santi M. Mandal,^a,d Debasis De,^b,c Sanat K. Roy,^c Ananta K. Ghosh,^d Shanker Ram^b,* and Amit K. Das^d*
^aCentral Research Facility, Indian Institute of Technology, Kharagpur 721302, W.B., India
^bMaterials Science Centre, Indian Institute of Technology, Kharagpur 721302, W.B., India. E-mail: sram@matsc.iitkgp.ernet.in
^cDepartment of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302, W.B., India
^dDepartment of Biotechnology, Indian Institute of Technology, Kharagpur 721302, W.B., India. E- mail: amitk@hijli.iitkgp.ernet.in

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been used extensively for the analysis of intact proteins and for proteomics. Proteins or proteomics analyses with low molecular mass range have some limitations because of background interference from the salt or surfactant ions. Lanthanum-calcium-manganate La_0.67Ca_0.33MnO₃ nanoparticles (LCMONPs) have been used as the matrix-assisting material after surface modification to reduce the salt or surfactant interference. The detectable mass range was tested in the range of 800–16,000 Da. The surface-modified LCMONPs have affinity with protein molecules through ionic or electrostatic interaction at pH 4.0. The nanoparticles mixed with proteins give a spectrum with a large signal-to-noise ratio for the analytes, and effectively eliminate the noise from interfering salt or surfactant ions. The results indicate that surface-modified La_0.67Ca_0.33MnO₃ nanoparticles can be used with MALDI matrix for proteins to eliminate the excessive noise of selective surfactants or salt ions from the MALDI spectrum.