... mitochon-drial respiratory chain, the assistance of specificchaperone proteins is also required. The available dataindicate that the accessory factor Bcs1p is involved in the binding of ISP to an immature ... strain, as expected, was respira-tory-deficient because of the absence of the catalyticsubunit ISP (Table 1). Figure 3A shows that a band of approximately 500 kDa was also found in this mutantstrain ... molecular mass calibration markersincluded thyroglobulin (670 kDa), apoferritin (440 kDa),catalase (230 kDa), alcohol dehydrogenase (150 kDa), con-albumin (78 kDa), albumin (66 kDa), and b-lactoglobulin(35...