A quantitative assay of peptide‐dependent class I assembly

Abstract

We have developed a quantitive assay for the measurement of class I assembly induced by peptide. We have applied this assay to H‐2D^b, K^b and HLA‐A2.1 with a panel of 49 overlapping peptides derived from HIV‐1 gag protein. We find that the effects of peptide on assembly form a continuous distribution. By defining positives as those that increase the concentration of folded heavy chains more than three standard deviations from the control we show that 7/48 bind A2.1, 11/49 bind D^b and 7/47 bind K^b. The assembly assay contrasts with solid‐phase assays in being more discriminating (fewer peptides binding any given class I molecule), and showing less overlap in the patterns of peptides bound by the three class I molecules.