Abstract
A method for measuring the ratio of diacyl phospholipid to protein in lipid-protein mixtures and membranes by infrared spectroscopy is described. Samples made of diacyl phospholipid and proteins mixed in known ratios were analyzed for lipid-protein ratio by the infrared (ir) method. Results had a standard deviation of less than ±4% over the lipid-protein molar ratio range of 9:1 to 320:1. Calculations of the ratio of total lipid to protein require that the diacyl phospholipid-to-protein ratio be divided by the mole fraction of diacyl phospholipid in the total lipid. Phospholipid-protein ratios for various sarcoplasmic reticulum membrane preparations ( R 1-washed, octylglucoside purified, deoxycholate treated) were determined by the ir method and compared to literature values. Also, phospholipid-protein ratios were determined for R 1-washed sarcoplasmic reticulum by three chemical analyses using different protein assays and were compared with ratios obtained by the infrared method. The infrared results were closest to those of a chemical method designed specifically for membrane proteins.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
