Abstract
Phospholipases A have been characterized in fetal rat epidermis. Both a calcium dependent phospholipase A with pH optimum of 8.5 and a calcium independent enzyme with a pH optimum of 4.5 were found. Activity against both acyl groups of phosphatidyl choline were found for both enzymes and the findings suggested that the acid enzyme (pH 4.5) is primarily phospholipase A1. The specificity of the alkaline enzyme with respect to acyl groups could not be determined due to the marked hydrolysis of lysophosphatidyl choline. Lysophospholipase activity had similar pH and calcium requirements as the alkaline phospholipase A and the 2 activities could not be dissociated in these experiments. The acid phospholipase was localized primarily in a fragile large particle fraction while the alkaline enzyme was present in various subcellular fractions and most active in the soluble supernatant. These findings demonstrate that epidermal phospholipases A are similar to those in other mammalian tissues. The presence of both acid and alkaline enzymes ar various subcellular loci suggest that the enzymes may play important roles in many facets of epidermal membrane metabolism and in particular in the degradative events of keratinization.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.