I've collected some things to proofread....
check for extra spaces between words
consistancy in fonts/style especially in titles
consistency in leaving spaces after titles
capitals consistent in titles
consistency of writing 5mg or 5 mg for anything with a unit
correct subscript/superscript e.g. in MgF3-
correct italics e.g. E. coli
both e.g. kcat
write times not X and laboratory not lab
in words such as sidechain, wildtype and stepwise check if it is one word, hyphenated or two words, and stick to one