%0 Journal Article %A Srivastava, Om P. %A Fitz-James, Philip %T Isolation and Characterization of a Unique Serine Protease from Bacillus cereus Spore Coats %D 1981 %J Microbiology, %V 126 %N 2 %P 463-475 %@ 1465-2080 %R https://doi.org/10.1099/00221287-126-2-463 %I Microbiology Society, %X A protease associated with spore coats of Bacillus cereus was extracted with 25 mM-dithioerythritol plus 2 M-urea at pH 9ยท0; and purified by ammonium sulphate fractionation and affinity chromatography. The spore protease differed from two intracellular proteases in pH optimum, pH stability, heat stability, stability in the presence of dithioerythritol and urea, molecular weight and in lack of reactivity with antibody to one of the intracellular proteases. The distinctive nature of the spore protease was also suggested by the fact that in a mutant with an altered intracellular protease, the properties of the spore protease remained unchanged. Inhibitor studies suggested that the spore protease was of the serine type with some similarities to trypsin. Two mutants were isolated with altered heat and pH stabilities of the spore protease; the intracellular proteases were unaltered. Spores produced by the mutants contained the same amount of coat protein per spore as the wild-type and germinated as well as the wild-type. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-126-2-463